12th Physics Class 12th Physics All Chapter MCQ Test 2026 33 12th Physics Chapter 1 MCQ Test तैयारी में दम हैं तो 25 में से 23 सही करों। 1 / 25 Plastic rod rubbed with fur and glass rod rubbed with silk Repel each other Mix up with each other Attract each other None of these 2 / 25 The ratio of electric flux density and electric field intensity is known as Gravitational constant Dielectric constant Both A and B None of these 3 / 25 The electric field intensity inside of hollow spherical charge conductor is Infinite Zero positive and greater than 1 None of these 4 / 25 Which of the following has unit volt / metre? Electric flux Electric potential Electric capacity Electric field 5 / 25 Which of the following physical quantities is a vector Electric flux Electric potential Electric potential energy Electric intensity 6 / 25 An electric dipole placed in a uniform electric field experience in general A force and a torque Only a force Only a torque None of these 7 / 25 When a body is charged its mass- Increases Decreases Remains same May increase or decrease 8 / 25 A surface enclosis and electric dipole the total electric flux over the surface is Infinite Zero Q None 9 / 25 If a sphere of bad conductor is given charge then it is distributed on Surface Surface and also inside the surface Only inside the surface None of these 10 / 25 The total charge on an electric dipole is Zero negative Positive Infinite 11 / 25 Voltmeter measures Resistance Potential difference Current None of these 12 / 25 The force acting on Per unit charge is called Electric current Electric potential Electric field Electric space 13 / 25 There are two identical spheres A and B .A is given +Q charge and b is given - Q charge Mass of A increases Mass of B increases No effect on mass None of these 14 / 25 An electric dipole placed in a non uniform electric field experience A force but not a torque A torque but not a force A force and a torque None of these 15 / 25 Positively charge body has Excess of electron Deficit of electrons Excess of protons Deficit of proton 16 / 25 Debye is a unit of Charge Potential Electric dipole moment None 17 / 25 Spherical conductor is charged the electric field intensity at its Centre will be Infinite Equal to that at the surface Zero None of these 18 / 25 Quantization of charge indicates that Charge which is a fraction of charge on an electron is not possible Charge cannot be destroyed Charge exist on particles There exist a minimum permissible charge on a particle 19 / 25 Force between two charged particle situated at a distance is F. If distance between the two is made half, then the value of electric force will be 4F 2F 1/4F 1/2F 20 / 25 There are two identical spheres A and B. A is given + Q charge and b is given - Q charge Mass of A increases Mass of B increases No effect on mass None of these 21 / 25 SI unit of electric dipole moment is CN Cm C C/m 22 / 25 A positively charge glass rod attract and object . The object must be Negatively charge Neutral Either negatively charge or neutral A magnet 23 / 25 Which of the laws given the force between two charges at rest Gauss theorem Kirchhoff's law Coulomb's law Faraday's law 24 / 25 Van De graaff generator is an electrostatic machine which produces Only high current Only high voltage High current and high voltage Low current and low voltage 25 / 25 Electric field lines provide information about Field strength Direction Nature of charge All of these Your score isThe average score is 39% 0% Restart quiz 9 12th Physics Chapter 2 MCQ Test तैयारी में दम है तो 37 में से 35 सही करके दिखाओं। 1 / 37 The work done by electric field on a charged taken from one point to another of an equipotential surface will be Positive Negative Zero None of these 2 / 37 When a body becomes negatively charged , its mass Decreases Increases Remains the same None of these 3 / 37 Two capacitor each of capacity C are connected in parallel .The equivalent capacity is 2C C C/2 1 4 / 37 The capacity of any conductor is C=qv C=v/q C=1/2qv C=q/v 5 / 37 If an earthed conductor is brought near an insulated conductor then the capacity of insulated conductor? Decreases Increases Remains unchanged None 6 / 37 In a region of constant potential The electric field is uniform The electric field is zero The electric field is infinite None of the 7 / 37 Three condenser each of capacity C are connected in the series then there equivalent capacity will be 3C 3 C/3 1 8 / 37 The dielectric constant of water is- 1 60 80 40 9 / 37 Van de graff generator is used for producing High current High voltage High power High capacity 10 / 37 The electric dipole moment per unit volume of a dielectric medium is called Polarization vector Electric flux Displacement Distance 11 / 37 An electron of charged e coulomb passes through a potential difference of V volt its energy in joule will be V eV e ve 12 / 37 Linear charge density is equal to Charge/surface area Charge/length Charge/volume None of these 13 / 37 If a dielectric slab is introduced in between the two plates of capacitor then its capacitance Increases Decreases Remain same Becomes zero 14 / 37 A dielectric constant 6 is to be filled in the gap between plates of a parallel plate capacitor. what is the factor by which the gap should be changed to maintain the same capacitance? 6 times 1/6times No change None of these 15 / 37 If a proton is brought near another proten then its potential energy- Increases Decreases Unchanged None 16 / 37 The dielectric constant of water is 80 60 40 20 17 / 37 Eight drops each of radius r and charge q of are merged to form a single drop . the ratio of the potential of big dropped to a small drop is 8:1 4:1 2:1 1:8 18 / 37 The capacitance of a parallel plate capacitor by the introduction of a dielectric between the plates of the capacitor. Increases Decreases Remain same Nothing can be said 19 / 37 Electric potential at the centre of a charged hollow metal sphere is Zero Twice at that on the surface Half of that on the surface Same as that on the surface 20 / 37 Three condenser of equal capacity C are connected first in parallel and then in series .the ratio of equivalent capacity in both conditions is- 9:1 6:1 3:1 1:9 21 / 37 When I show bubble is charged its radius will Increases Decreases Remains the same Because zero 22 / 37 When a medium of dielectric constant k fills the gap between the plates of a capacitor its capacitance compared to air filled state- Increases K times Decreases K times Both None 23 / 37 A point charge q is rotated around another point charge Q in a circular path work done by electric field on it will be Zero Positive Negative None 24 / 37 The net charge on a charged capacitor is Zero 1 1C Infinite 25 / 37 The loss of energy taking place due to sharing of charge between two conductors depends upon Potential difference Square of potential difference Capacitance Square of current 26 / 37 If a dielectric is placed between two plates of a parallel plate capacitor, the value of capacitance- Increases Remains constant Decreases None of these 27 / 37 Electric potential of earth is taken to be zero because the earth is good Semiconductor Conductor Insulator None of these 28 / 37 The capacitance of a spherical capacitor is directly proportional to its Radius 1 0 None 29 / 37 If the distance between the two charges is increased then the electrostatic potential energy of the charges Decreases Increases May increase or decrease Same 30 / 37 The value of electric field inside a charge is spherical conductor is Q Zero E π 31 / 37 Potential gradient is equal to dx/dv dx.dv dv/dx None 32 / 37 The value of electric potential at a distance r from a point charge is Proportional to r Inversely proportional to r Proportional to r square Inversely proportional to r square 33 / 37 Dielectric constant for vacuum is 1 Infinity 2.3 4.7 34 / 37 Sum of charges on collecting and conducting plate of a charged capacitor is- Zero 1 Infinite 50 35 / 37 Which are the following value of n is not possible in relation Q= ne? 4 8 2 4.2 36 / 37 The electric potential inside the charged the hollow sphere is- Zero Uniform Infinite None of these 37 / 37 The electric potential due to electric dipole at the point lies on the bisector of its axis is- 1 Zero Infinite 100 Your score isThe average score is 64% 0% Restart quiz 5 12th Physics Chapter 3 MCQ Test तैयारी में दम है तो 35 में से 33 सही करके दिखाओं। 1 / 35 The equivalent resistance of resistor in parallel combination Increases Decreases Remain same None of these 2 / 35 Colour code of carbon resistance for blue colour is 4 3 8 6 3 / 35 The value of red colour in colour code of carbon resistance is 0 4 2 8 4 / 35 The spacific resistance of a conductor increases with- Increase of temperature Increase of cross sectional area Decrease in length Decrease of cross sectional area 5 / 35 Which of the following is conserved is kirchhoff's law? Energy Force Charge Potential 6 / 35 The algebraic sum of all current meeting at any point in an electrical circuit is Infinite Positive Negative Zero 7 / 35 Value of green colour code on carbon resistance is 3 4 5 6 8 / 35 Electric current density is a Vector quantity Scalar quantity Both None of these 9 / 35 Wheatstone bridge compares Resistances Current Potential difference All of these 10 / 35 Which law follows the law of conservation of energy Lenz's law Kirchhoff's law Maxwell law None 11 / 35 The length of wire is doubled its conductance will be Remains unchanged Halved Double None of these 12 / 35 Kirchhoff's loop rule is based on conservation of Mass Charge Energy None of these 13 / 35 Amphere hour is unit of Power Charge Energy Potential difference 14 / 35 Amphere is equal to Joule/second Coulomb/second Volt/coulomb Joule/coulomb 15 / 35 Which of the following is the best conductor of electricity? Silver Gold Aluminium Zinc 16 / 35 The length of wire is doubled its conductance will be Remains unchanged Halved Double None of these 17 / 35 Kirchhoff's junction rule is based on conversation of Mass Charge Energy All 18 / 35 The electrical appliances in our houses are connected across supply switch in Series Parallel Mixed grouping None of these 19 / 35 Electric current is a scalar quantity because It obey the law of vector addition It does not obey loss of vector addition It obey The law of inertia None of these 20 / 35 Kilowatt-hour is unit of Electric power Electric energy Torque Electric current 21 / 35 Ohm's law is followed by Conductor Semiconductor Insulator All of these 22 / 35 Which one is correct? Current is a scalar and current density is a vector Current is the vector and current density is scalar Both the quantities are vectors None of these 23 / 35 On cooling the resistivity of metals Increases Decreases Both None 24 / 35 Unit of electromotive force is Newton Joule Volt Metre 25 / 35 The resistivity of material of a conductor depends on Length Cross sectional area Temperature None of these 26 / 35 The motion of electron inside the conductor is Uniform Accelerated Drifting Decelerated 27 / 35 The value of yellow colour in colour code of carbon resistance is 1 3 4 8 28 / 35 As the temperature rises the resistance offered by metals Increases Decreases Remain same None of these 29 / 35 Colour code of carbon resistance for white is 5 6 8 9 30 / 35 Wheatstone bridge is used in the measurement of E.m.f Current Resistance Charge 31 / 35 Which of the following is the same in parallel connection of resistances? Potential difference Current Both potential difference and current None of these 32 / 35 Electric current is a Vector quantity Scalar quantity Tensor None of these 33 / 35 Ohm's law is valid when the temperature of conductor is Very low Very high Different Constant 34 / 35 What is mainly measured by potentiometer? Current Resistance Potential difference All of these 35 / 35 Specific resistance for a wire depends upon Length Cross section area Mass None of these Your score isThe average score is 49% 0% Restart quiz 12th Physics Chapter 4 MCQ Test तैयारी में दम है तो 35 में से 33 सही करके दिखाओं। 1 / 35 A charged particle moves perpendicular to a magnetic field It's momentum and kinetic energy are constant It's kinetic energy changes but its momentum is constant It's momentum changes but kinetic energy is constant None of these 2 / 35 When an ammeter is shunted , it's measuring range Increases Decreases Remains constant None of these 3 / 35 For two magnetic force field tangent law holds good when the angle between them is- 45° 90° 0° 180° 4 / 35 A charge moving with uniform velocity produces- Only an electric field Only a magnetic field Electromagnetic field None of these 5 / 35 To parallel conductors carrying current in the same direction will Attract each other Repel each other Both None of these 6 / 35 Current sensitivity of a moving coil galvanometer is NBA/CR NBA/C NBA None of these 7 / 35 The resistance of a galvanometer is Deep a current of 1% (or 1/100 part) of main current will pass through it if the shunt is G/100 G/99 G/67 G77 8 / 35 Resistance of ideal ammeter is Infinity Zero 100 ohm 50 ohm 9 / 35 If any ammeter is shunted then the total resistance of the circuit Increases Decreases Remain same None of these 10 / 35 A charged particle is released from rest in a combined parallel electric and magnetic fields the motion will be In a straight line In a circle In a helix In rectangle 11 / 35 On using shunt , the sensitivity of galvanometer- Decreases Increases No change None of these 12 / 35 The law , governing the force acting between two electric charges known as Ampere's law Ohm's law Faraday's law Coulomb's law 13 / 35 An electron enters perpendicularly to a uniform magnetic field the path of the electron will be Circular Perpendicular Linear Spiral 14 / 35 Where are charged particle enters a magnetic field, its kinetic energy Remains constant Increases Decreases Becomes zero 15 / 35 The magnetic field due to a long solenoid is Directly proportional to N Directly proportional to N square Inversely proportional to N Independence of N 16 / 35 The S.I. unit of magnetic field or magnetic induction is Tesla Weber Henry Newton 17 / 35 Magnetic field due to a toroidal solenoid is independent of Its number of turns Electric current Radius None of these 18 / 35 The force between two moving charges is Only coulomb force Both magnetic force and electric force Nuclear force None of these 19 / 35 50 particle enters into a magnetic field at 30° with induction vector. It's path becomes Circular Helical Elliptical Line 20 / 35 Tesla is unit of ? Electric flux Magnetic flux Magnetic field Electric field 21 / 35 A charged particle is given a motion along the magnitude field line . The force acting on the particle will be In the direction of velocity In a direction opposite to velocity Perpendicular to velocity Zero 22 / 35 Which are the following relation between 'G' the resistance of galvanometer and V the resistance of voltmeter is correct? V>G G>V Both None 23 / 35 The unit of voltage sensitivity is Rad rad/metre rad/volt None of these 24 / 35 The resistance of ammeter is Very small Very large Extra small Extra large 25 / 35 When and ammeter is shunted its total resistance in the circuit Increases Decreases Remains unchanged None of these 26 / 35 If the current in an ideal solenoid be doubled , the magnitude of magnetic induction at a point in the solenoid will Get doubled Remain the same Both None of these 27 / 35 Current in two parallel wires are directed opposite to each other. These wires Repel each other Attract wach other Exert no force on each other Destroy the currents of each other 28 / 35 A circular coil of radius r carries a current I. The magnetic field at its centre is B . At what distance from the centre on the axis of the coal the magnetic field will be B/8 √2R √3R 2R 3R 29 / 35 Current sensitivity of a moving coil galvanometer can be increased by Increasing the number of turns Increasing the magnetic field Increasing the area of coil All of above 30 / 35 Current sensitivity depends on Number of turns Strength of magnetic field Area of coil All of above 31 / 35 In a vertical wire current flows from lower to upper. If an electron beam is sent horizontally towards wire than deflection will be Right side Upward Downward Left side 32 / 35 The radius of a circular current loop is made double and the current is made half. the magnetic moment of the loop will become Halved Doubled Four times large None of these 33 / 35 Gauss is a unit of Magnetic field Magnetic induction Both A and B None of these 34 / 35 If a current is passed through spring the spring will Be stretched Be compressed Remain as it is None of these 35 / 35 Voltage sensitivity of a voltmeter is- NBA/CR NBA/C NBA C Your score isThe average score is 46% 0% Restart quiz 3 12th Physics Chapter 5 MCQ Test तैयारी में दम है तो 21 में से 19 सही करके दिखाओं। 1 / 35 Which is more appropriate material for a strong electromagnet? Air Soft iron Steel Allow 2 / 35 The angle between magnetic meridian and geographical meridian is called Angle of dip Declination Horizontal component of magnetic field Apparent angle of dip 3 / 35 The value of magnetic susceptibility of vacuum is Equal to 0.5 Infinite 1 Zero 4 / 35 Liquid and gases are not - Ferromagnetic Diamagnetic Paramagnetic None of these 5 / 35 The angle between the magnetic dipole moment and magnetic induction at the axis of circular current is - 0° π 2 100000 6 / 35 The origin of magnetism in a magnet is Spin of electron Cosmic rays Presence of a big magnet in the earth The earth 7 / 35 The angle between the geographic meridian and the magnetic meridian is called Inclination Declination Dip None of these 8 / 35 Which of the following is not a magnetic element of the earth at a place ? Declination Dip Magnetic moment Horizontal component of Earth's magnetic field 9 / 35 At any point on the perpendicular bisector of a bar magnet Magnetic field is zero Magnetic potential is zero Field and Potential both are zero None of these 10 / 35 When magnetic moment of an oscillating magnet increases, its time period will - Increases Decreases Remains unchanged None of these 11 / 35 Which of the following has higher magnetic susceptibility Diamagnetic Paramagnetic Ferromagnetic None 12 / 35 The magnetic field is strength of a magnet is the greatest at The centre The poles Infinity None of these 13 / 35 The magnetic susceptibility of air is Positive Negative Zero None of these 14 / 35 Angle between the Earth's magnetic axis and Earth's geographic axis is about Zero 11° 1 None 15 / 35 The value of magnetic force field at the surface of earth is - 0.5 gauss 2 gauss 4 gauss None of these 16 / 35 If a bar magnet is cut into two parts perpendicular to its length , for one part , which of the following will not change? Pole strength Moment of inertia Magnetic moment Magnetic length 17 / 35 Magnetic lines of force of straight current are- Circular around current Straight and parallel to current Both None of these 18 / 35 The apparent dip at a place is always Greater than true dip Less than true dip Equal to true dip None of these 19 / 35 To make an electromagnetic material should have- Higher magnetic susceptibility Higher retentivity Lower attentivity None of these 20 / 35 Direction of the magnetic induction at an axial point and magnetic moment of a bar magnet are Parallel Anti parallel Mutually perpendicular None of these 21 / 35 Iron is - Paramagnetic Diamagnetic Ferromagnetic Non magnetic 22 / 35 When the intensity of magnetic field is increased four times , the time period of suspended magnetic needle becomes. Double Half Four times One time 23 / 35 Magnetic dipole moment is a vector quantity directed from: South to North pole North to south pole East to west direction West to east direction 24 / 35 The angle between total field and horizontal field in magnetic meridian at a place is called Declineation Dip Horizontal component of Earth's field None of these 25 / 35 Curie temperature is that below which A ferromagnetic substance become paramagnetic Ferromagnetic substance become diamagnetic Paramagnetic substance become diamagnetic A Ferromagnetic substance remains ferromagnetic 26 / 35 Nickel is Paramagnetic Diamagnetic Ferromagnetic None of these 27 / 35 Copper is - Paramagnetic Ferromagnetic Diamagnetic None of these 28 / 35 Which of the following will have negative magnetic susceptibility? Paramagnetic Diamagnetic Ferromagnetic None of these 29 / 35 Which quality should be present for making permanent magnet? High coercivity Less coercivity High magnetic retentivity A and C both 30 / 35 The magnetic moment of a bar magnet is M . It is bent at 60° from middle then magnetic moment will become - M M/3 M/2 None of these 31 / 35 Which pair has the same S.I dimensions? Magnetic field intensity and magnetization Magnetization and susceptibility Susceptibility and permeability None of these 32 / 35 The resistance of an ideal voltmeter is - Infinite Zero 500000 9 33 / 35 The permeability of a ferromagnet Depends upon magnetic field Is independent of magnetic field Is proportional to magnetic field None of these 34 / 35 Ongoing from north pole to equator, the value of angle of dip Remains constant Increases Decreases First decreases and then increases 35 / 35 In making permanent magnet we use - Steel Copper Soft iron None of these Your score isThe average score is 24% 0% Restart quiz 1 12th Physics Chapter 6 MCQ Test तैयारी में दम है तो 35 में से 33 सही करके दिखाओं। 1 / 35 Lenz's law is associated with Charge Mass Energy Principle of conservation of momentum 2 / 35 Lenz's law is derived from Kepler's law Newton's law Coulomb's law Faraday's law 3 / 35 Direction of Eddy current is obtained from - Kirchhoff's rule Lenz's law Plank's law None of these 4 / 35 Calculate the magnetic flux when the magnetic field is perpendicular to the surface area . Minimum Maximum Zero Depend on the surface area 5 / 35 The role of self induction is equivalent to Momentum Force Energy Inertia 6 / 35 The current passing through a choke coil is 5H age decreasing at the rate of 3A/s . The emf induced in coil is 1.67 V -15V Both None of these 7 / 35 The mutual induction of two nearby coins is 1.5 H. If in one of these coils, the current grows from zero to 20A in 0.5s, the flux linked with second qual changes by 10v 9V None of these 30Wb 8 / 35 Factors that affect the voltage generation in faraday's experiment is Number of coils Changing magnetic field Changing environment Option A and B 9 / 35 SI unit of mutual induction is - Henry Ohm Tesla None of these 10 / 35 The working of an induction coil is based on the principle of Homogenity Electromagnetic induction Self induction None of these 11 / 35 The rate of change of magnetic flux in a loop is equal to - emf induced Current induced Electric field induced None of these 12 / 35 The SI unit of magnetic flux is Kilogram Weber Second Candela 13 / 35 To convert mechanical energy into electrical energy are can use DC dynamic AC motor Motor Transformer 14 / 35 Inductance is the Scalar quantity Vector quantity Both a and b None of these 15 / 35 An inductor may store energy in its Electric field Magnetic field Both None of these 16 / 35 Which physical quantity has SI unit Henry ? Self inductance Mutual inductance Both None 17 / 35 The working of dynamo is based on the principle of Heating effect of current Electromagnetic induction Magnetic induction Electric induction 18 / 35 If a denial cell is connected across the primary coil, the change in flux in the secondary will be 19 20 Zero None of these 19 / 35 Calculate the magnetic flux produced when the magnetic field is parallel to the surface area. Maximum Minimum Zero None of these 20 / 35 The relative motion between the magnet and the coil that is responsible for generation of Magnetic field in the coil Current in the coil Voltage in the coil None of these 21 / 35 Magnetic flux per unit area is Magnetic field Magnetic field density Both None of these 22 / 35 A circular coil is held in vertical plane. Bar magnet is taken towards it with north pole towards coil. Direction of current as scene from the side of magnet is Anticlockwise Clockwise First anti clock wise and then clock wise First clockwise and their anti clock wise 23 / 35 The magnetic flux linked with a coil is changed from 1Wb to 0.1Wb in 0.1s. The induced emf is 4H 9V Both None of these 24 / 35 The phenomena called electromagnetic induction was first investigated by Newton Kepler Faraday None of these 25 / 35 An induction coil gives High voltage at high current High voltage at low current A low voltage at high current A low voltage at low current 26 / 35 When the rate of change of current is unity, The induced emf is equal to Thickness of coil Number of turns in coil Coefficient of self inductance Total flux linked with coil 27 / 35 The principle of mutual induction is used in Transformer Induction coil Both None of these 28 / 35 Instrument which converts mechanical energy into electrical energy is - Induction coil Dynamo Transformer Motor 29 / 35 Lenz's law is the result of which principle of conservation? Current Energy Momentum Charge 30 / 35 Which of the following is consequences of the law of energy conservation? Lenz's law Faraday's law Ampere's law None of these 31 / 35 The law of electromagnetic induction was discovered by Faraday Fleming Lenz Rumkorff 32 / 35 When current in a coil changes from 5A to 2A in 0.1s then average voltage of 50V is produced. The self induction of the coal is 1.67 henry 6 henry 3 henry None of these 33 / 35 The law related with electromagnetic induction is called Newton's law Faraday's law Ohm's law Ampere's law 34 / 35 SI unit of magnetic flux is Weber Watt Tesla Joule 35 / 35 Magnetic flux is the Vector quantity Scalar quantity Tensor quantity None of these Your score isThe average score is 51% 0% Restart quiz 1 12th Physics Chapter 7 MCQ Test तैयारी में दम है तो 36 में से 34 सही करके दिखाओं। 1 / 36 For resonance condition in any L-C-R circuit, the phase difference between applied voltage and current is π π/2 5 Zero 2 / 36 In step up transformer, the value of current and secondary coil compared to primary coil is Equal Less More None of these 3 / 36 The phase difference between current and voltage in only capacitive alternating current circuit is 0° 90° 180° None of these 4 / 36 Power factor is equal to R/Z R Z None of these 5 / 36 Inductive reactance for direct current is Zero Infinity Both None of these 6 / 36 Power factor for pure inductance is - 1 0 Infinity None of these 7 / 36 Power factor for wattless current is 0 Infinity Both None 8 / 36 If there are N1 and N2 turns in the primary and secondary coils respectively in a step down transformer, then N1>N2 N2>N1 N1=N2 None of these 9 / 36 Efficiency of transformer is the ratio of - Output voltage to input voltage Number of turns in secondary to number of turns in primary Output power to input current Output power to input power 10 / 36 The core of a transformer is laminated to stop Eddy currents Mass loss Magnetization None of these 11 / 36 The face difference between the current passing through an inductor and voltage across the inductor is an a.c circuit is 0 π/2 2 None of these 12 / 36 For which of the following, capacitor works as infinite resistance? DC AC Both None of these 13 / 36 L-C circuit is called- Oscillatory circuit Drift circuit Both None 14 / 36 Which of the following is correct for transformer ? It converts A.C into D.C It converts D.C into A.C It increases or decreases D.C voltage It increases or decreases A.C voltage 15 / 36 The power factor of series LCR circuit is R Z/R R/Z RZ 16 / 36 The power factor of a series LCR circuit is R Z/R R/Z RZ 17 / 36 A choke coil has High inductance and high resistance High inductance and low resistance Low inductance and low resistance None of these 18 / 36 A choke coil is used to control A.C D.C Both A.C and D.C None of these 19 / 36 Alternating current of 3A is the same as 3 coulomb/ metre 3 ohm / metre 3 joule / coulomb None of these 20 / 36 An A.C circuit containing only resistance , Voltage and current have the same frequency Voltage and current have same phase difference Voltage and current have same phase difference π None of these 21 / 36 An A.C circuit containing only resistance, which is not correct. The resistor causes to unknown reversible conversion of electrical energy to thermal energy Voltage and current have the same frequency Voltage and current are in phase Voltage and current have pd.π/2 22 / 36 Alternating current can be produced by A transformer An electric motor Heating effect A dynamo 23 / 36 Alternating current shows Chemical effect Magnetic effect Heating effect All the above 24 / 36 The frequency of A.C in India is 25 HZ 50 HZ 30 HZ 60HZ 25 / 36 The power factor is for Pure resistor only Pure indicator only Pure capacitor only None of these 26 / 36 Reactance of the capacitor with the frequency of alternating current. Decreases Increases Either decreases or increases None of these 27 / 36 The thermal effect of alternating current is practically Joule heating Peltier heating Thomson effect None of these 28 / 36 For long distance power transmission by using a transformer, the transformer at the source should be Step up Step down Any of A and B None of these 29 / 36 Induction furnace is based on the principle of Eddy current Self induction Mutual induction None of these 30 / 36 S.I unit of impedance is - Henry Ohm Tesla None 31 / 36 Transformer works utilise Self induction Mutual induction Heating None of these 32 / 36 A transformer works on D.C only A.C only Both None 33 / 36 Which of the following material is most suitable to be used for making the core of a transformer. Soft iron Copper Stainless steel Alnico 34 / 36 In LCR circuit energy laws in circuit is - In inductance In resistance In condenser None of theseNone of these 35 / 36 The core of transformer is laminated to prevent - Energy loss Mass loss Charge loss None of these 36 / 36 By use of a capacitor in induction coil, the emf in secondary is Increased Decreased Not changed Reduced to zero Your score isThe average score is 33% 0% Restart quiz 0 12th Physics Chapter 8 MCQ Test तैयारी में दम है तो 35 में से 33 सही करके दिखाओं। 1 / 35 The electric field E , magnetic field B and speed of wave c are related together as B= cE C=BE E=Bc None of these 2 / 35 The average intensity I, mean energy density u and speed c of an electromagnetic wave in free space are related together as I=cu Ic=u Iu=c None of these 3 / 35 The energy of an electromagnetic radiation is 13.2keV. This radiation is related to which region of spectrum? Visible X-rays Ultraviolet Infrared 4 / 35 Electromagnetic waves can be - Light X-rays Infrared All the these 5 / 35 Which of the following waves has a maximum frequency ? Infrared waves Gamma rays Microwaves Radio waves 6 / 35 Clouds reflect - Micro waves Radio waves Infrared rays Ultraviolet waves 7 / 35 What is the phase difference between electric and magnetic fields in an electromagnetic wave ? 0 1 2 π 8 / 35 X-rays are capable of penetrating Bones Metallic materials Human flesh All of above 9 / 35 Nature of electromagnetic waves is - Transverse Longitudinal Both None of these 10 / 35 Which of the following prove that electromagnetic waves are transverse? Reflection Diffraction Interference Polarization 11 / 35 In an electromagnetic wave, the disturbance is (are) E only B only Both E and B None of these 12 / 35 Which is correct for velocity of light ? E/B B √E E.B 13 / 35 Which type of e.m. wave is used for treatment of muscular strain? Infrared rays Ultraviolet rays Radio waves Microwaves 14 / 35 Which one of the following is used to investigate the structure of solids? Gamma rays Infrared rays X rays Cosmic rays 15 / 35 Infrared rays are between the regions - Radio waves and microwaves Microwaves and visible light Visible light and ultraviolet regions None of these 16 / 35 Which rays are used for cooking and heating - Infrared Ultraviolet Microwave None of these 17 / 35 The energy of an electromagnetic field is due to its Wavelength Frequency Electric and magnetic fields None of these 18 / 35 Which of the following help us for recognization of precious stone? Ultraviolet rays Infrared X-rays None 19 / 35 Which type of e.m. wave is used for purification of water? Infrared rays Ultraviolet rays Radio wave All of above 20 / 35 Which of the following is not electromagnetic wave ? Light waves X-rays Sound waves Infrared rays 21 / 35 Which of the following are used to make labs free from bacteria? U-V rays I-R rays X-rays None 22 / 35 The phase difference between electric and magnetic fields in an electromagnetic wave is- 0 π/2 π Anything 23 / 35 Which of the following is not shown by electromagnetic wave? Reflection Polarization Diffraction None of these 24 / 35 The phase difference between electric wave and magnetic wave in the electromagnetic wave is 2 π/2 9 Zero 25 / 35 X-rays are Moving electron Moving positive ion Moving negative ion Electromagnetic waves 26 / 35 Electromagnetic wave in free space is Longitudinal Transverse Progressive None of these 27 / 35 Water molecule in foods have a rotational frequency in the range of Ultraviolet waves Infrared waves Microwaves Visible waves 28 / 35 Nature of electromagnetic wave is - Longitudinal Transverse Neither longitudinal not transverse Both transverse and longitudinal 29 / 35 According to the law of electromagnetism, the speed of electromagnetism in all the inertial frames is - Same Different Not definite None of these 30 / 35 Maxwell equations represent four laws of electromagnetism. Maxwell amphere law relates To total current To displacement current To conduction current None of these 31 / 35 The ratio of the Speeds of microwaves and X-rays in vacuum is 1:2 1:4 1:1 None of these 32 / 35 A Displacement current is produced Only by a varrying magnetic field Only by a varrying electric field By varrying electric and by a varying magnetic field None of these 33 / 35 Which is a wrong statement ? Electromagnetic waves are transverse. Electromagnetic waves travel in a vacuum at a speed of light The speed of electromagnetic wave is the same in all media Electromagnetic waves are emitted by accelerated charges 34 / 35 According to Maxwell's hypothesis, changing electric field gives rise to? Introduced EMF Electric field Magnetic field None 35 / 35 Main effect of infrared waves is Sensation of vision Thermal effect Photoelectric effect None of these Your score isThe average score is 0% 0% Restart quiz 1 12th Physics Chapter 9 MCQ Test तैयारी में दम है तो 35 में से 33 सही करके दिखाओं। 1 / 35 The focal length of plane mirror is- Unity Infinity Zero None of these 2 / 35 When concave lens of glass is immersed in water , it becomes Less convergent Convergent Less divergent More divergent 3 / 35 Lesser beam is Highly monochromatic Depends on the energy Without direction wave None of these 4 / 35 To remove hypermetropia (long sightedness) lens used is- Convex Concave Cylindrical Plano-convex 5 / 35 Rainbow is a natural example of Refraction Reflection Refraction reflection and dispersion None of these 6 / 35 When a Ray of light enters a glass slab its wavelength Decreases Increases Remains unchanged Data are not complete 7 / 35 The lens which is used to remove short sightedness is Concave Convex Cylindrical Plano-convex 8 / 35 Which of the following phenomena taken place when a monochromatic light is incident on a prism? Dispersion Deviation Interference All of the above 9 / 35 When any convex lens is drown into water then its power Increases Decreases Equals Infinity 10 / 35 The optical fibre works on the principle of Scattering Refraction Dispersion Total internal reflection 11 / 35 A convex lens is dipped in a liquid, whose refractive index is equal to refractive index of material of lens, then it's focal length will - Becomes zero Become infinite Decreases Increases 12 / 35 Which has larger difference in focal length between eye lens and objective lens ? In telescope Compound microscope In both None of these 13 / 35 When the tube length of microscope is increased, it's magnifying power Increases Decreases Becomes zero Remains unchanged 14 / 35 Optical fibre communication is based on which of the following phenomena- Total internal reflection Scattering Reflection Interference 15 / 35 The power of a convex lens of focal length 10 cm will be -10D +10D 95D +5D 16 / 35 Or increasing the length of the tube of compound microscope, magnifying power Increases Decreases Does not change Becomes zero 17 / 35 SI unit of power of lens is - Joule Candela Dioptre Watt 18 / 35 To overcome astigmatism lens used is - Concave lens Convex lens Cylindrical None of these 19 / 35 An air bubble inside water works as- Diverging lens Diverging mirror Convex lens None of these 20 / 35 Cylindrical lens is used to correct - Myopia Hypermetropia Presbyopia Astigmatism 21 / 35 The power of convex lens of focal length 20 cm in dioptre is 4 5 3 2 22 / 35 Minimum distance between real image formed by convex lens and object is- Four times Two times Three times of focal length None of these 23 / 35 Magnification is the ratio of - Image height to object height Image distance to object distance from focus Focal length to image distance None of these 24 / 35 When there is a refraction of light then which of the following does not change? Wavelength Frequency Speed Amplitude 25 / 35 The image formed by objective lens of a compound microscope is- Virtual and diminished Real and diminished Real and large Virtual and large 26 / 35 The radius curvature of plane mirror is Zero 5 Infinite None of these 27 / 35 The final image in astronomical telescope is Real and erect Real and inverted Virtual and inverted Virtual and erect 28 / 35 Cause of mirage is Refraction and total internal reflection Diffraction Scattering Interference 29 / 35 The magnifying power of a magnifying glass of power 12 dioptre is 4 1200 3 25 30 / 35 When length of compound microscope increases its magnifying power- Decreases Increases Becomes zero None of these 31 / 35 The dispersive power of a prism depends upon - Refracting angle of prism Nature of material of prism Breadth of base of prism Angle of incidence 32 / 35 The refractive index of diamond is about 1 2 2.42 3 33 / 35 The radius of curvature of a spherical mirror is 40cm . It's focal length will be 30cm 20cm 10cm None of these 34 / 35 For which of the following pairs is the critical angle the smallest? Water-air Glass-water Glass-air Glass-glass 35 / 35 In plane mirror, the image is - Always virtual Always real Both A and B are correct None of these Your score isThe average score is 25% 0% Restart quiz 0 12th Physics Chapter 10 MCQ Test तैयारी में दम है तो 35 में से 33 सही करके दिखाओं। 1 / 35 Polaroid glasses are used in sunglasses because They are cheaper They have a good colour They look fashionable They reduce the light intensity to half on account of polarization 2 / 35 Who discovered poisson's bright spot? Fresnel Rayleigh Fraunhofer Poisson 3 / 35 The phase difference of the waves for constructive interference of light is Odd multiple of π Even multiple of π Integer multiple of π None of these 4 / 35 The reason for the phenomenon of interference is Phase difference Change in amplitude Velocity change Intensity change 5 / 35 Huygen's assumed light wave to be Longitudinal Transverse Both None 6 / 35 In a young's double split experiment if red light is replaced by yellow light the Fringe width Increases Decreases Firstly increase then decrease None of these 7 / 35 Interference of light is the redistribution of which of the following physical quantities ? Frequency Intensity Wavelength Speed 8 / 35 Which of the following confirms transverse wave nature of light ? Interference Reflection Polarisation Dispersion 9 / 35 When two light waves interfere there at some points there is brightness and at some point there is darkness where energy goes at those point Convert into heat There is redistribution of light energy Transformation of heat energy into electrical energy None of these 10 / 35 The width of diffraction fringes is ______ to the width of interference fringes . Equal Unequal Similar None of these 11 / 35 Polarization can be done of electric magnetic wave By lens By mirror By Polaroid By prism 12 / 35 When the distance between source of light and screen is increased the Fringe width Increases Decreases Remain same None of these 13 / 35 If a thin transparent sheet is placed before young's double slit then width of fringe Increases Decreases Remains unchanged None 14 / 35 The wavefron due to a line source at finite distance from the source is Spherical Cylindrical Plane Circular 15 / 35 Which of the following will not cause of polarisation? Reflection Double refraction Scattering Diffraction 16 / 35 The phase difference of the waves for destructive interference of light is Odd multiple of π Even multiple of π Integer multiple of π None of these 17 / 35 The wave from due to a point source at an infinite distance from the source is Spherical Cylindrical Plane Circular 18 / 35 What is the geometric shape of the wavefron that originates when a plane wave passes through a convex lens? Converging spherical Diverging spherical Plane None of the above 19 / 35 What is the locus of all the particles in a medium vibrating in the same phase called? Fringe Wavelet Wavefront None of these 20 / 35 Light waves coming from two electric bulb do not interfere because they are Coherent Not coherent Not equal None of these 21 / 35 The wave front due to and unknown source at an infinite distance from the source is spherical Cylindrical Plane Circular 22 / 35 If in young's double slit experiment distance between split & screen is made half than width of fringe will - Remain same Become half Four times None of these 23 / 35 The concept of secondary wavelets was given by Fresnel Maxwell Huygens Newton 24 / 35 The resolving power of human eye in minute is 1/60 1 10 4 25 / 35 The nature of light waves is Longitudinal Transverse Sometimes transverse and sometimes longitudinal None of these 26 / 35 Huygen's secondary wave principle is used to New geometrical position of Wevefront Explain the superposition principle of waves Explain the interference of light Explain the polarization of light 27 / 35 The wavefront due to a point source at a finite distance from the source is Spherical Cylindrical Plane Circular 28 / 35 In the interference of waves Energy is dissipated in totality Energy is created in totality Energy is neither lost nor created there is only a redistribution of energy Nothing can be said 29 / 35 Which of the following factors does the intensity of light depend on? Frequency Wavelength Amplitude Velocity 30 / 35 Which of the following light phenomena confirms the transverse nature of light? Refraction of light Diffraction of light Dispersion of light Polarization of light 31 / 35 Light is a transverse wave because it shows Reflection Polarization Interference Diffraction 32 / 35 Two light sources are set to be coherent when both the sources of light emit light of The same amplitude and phase The same intensity and wavelength The same speed The safe wave length and constant phase difference 33 / 35 Which is used to produce polarised light? Prism of flint glass NaCl prism Nicol prism Biprism 34 / 35 The wave theory failed to explain Interference Diffraction Polarisation All of these 35 / 35 In interference there is redistribution of Mechanical energy Light energy Heat energy None of these Your score isThe average score is 0% 0% Restart quiz 0 12th Physics Chapter 11 MCQ Test तैयारी में दम है तो 35 में से 33 सही करके दिखाओं। 1 / 35 In photoelectric effect, the photoelectric current is independent of Intensity of incident light Potential difference applied between two electrodes The nature of emitter material Frequency of incident light 2 / 35 The maximum kinetic energy of photoelectrons emitted ine photoelectric effect depends linearly upon Square of frequency of incident light Frequency of incident light Wavelength of incident light Square of wavelength of incident light 3 / 35 Work function of silver is 4.70eV 4.60eV G Ev 4 / 35 When light enters from one medium into another medium, which quantity does not change ? Wavelength Frequency Speed Amplitude 5 / 35 Which of the following does the wave theory of light not explain? Diffraction Photocurrent Polarization Interference 6 / 35 The energy of a photon is 1MeV . Which part of electromagnetic spectrum will it belong to ? X-rays Y-rays Microwave None of these 7 / 35 Energy of photon is equal to hv H Hb V 8 / 35 What does a cathode ray consist of? Electrons Protons Photons Alpha particles 9 / 35 Which of the following Photon is of greater energy? Visible Infrared Ultraviolet None of these 10 / 35 Electron volt is a unit of Charge Potential difference Current Energy 11 / 35 A photoelectric cell is a device which Converts light energy into electricity Convert electricity into light energy Stores light energy Stores electricity 12 / 35 Which one of the following deflected in electric field? Gamma rays X-rays Ultraviolet rays Cathode rays 13 / 35 The nature that was established by Davisson-Germer experiment, was Partical nature Wave nature Charge particles None of these 14 / 35 If the intensity of the radiation incident on a photosensitive plate is doubled, how does the stopping potential change? Increases Decreases No effect Infinite 15 / 35 To beams one of red light and other of blue light of the same intensity are incident on a metallic surface to emit photo electrons which emits electron of greater frequency? red light Blue light Both None 16 / 35 The photoelectric effect is based on the law of conservation of Energy Momentum Mass Angular momentum 17 / 35 For same wavelength of electron and proton which physical quantity will be same ? Velocity Energy Momentum Angular momentum 18 / 35 Who gave the theory of quantization of electric charge? JJ Thomson William crooks RA millikan William 19 / 35 Photon does not possess Energy Momentum Rest mass Frequency 20 / 35 If the intensity of incident radiation in a photo cell is increased how does the stopping potential vary? Increases Remains same Decreases Infinite 21 / 35 The phenomena in which electrons are emitted from some metal surfaces when light falls on them is known as Photoelectric effect Photography Photometry Photosynthesis 22 / 35 De Broglie relation is true for all Charge particles Uncharged particles Particles whether charged or uncharged None of these 23 / 35 An electron and a photon each have a wavelength of 1.00nm. which has greater momentum? Electron Photon Both have equal value of momentum None of these 24 / 35 Work function of copper is- 4.65 2.75 4.17 None 25 / 35 Matter waves are associated with material particles only if they Are in motion Are not in motion Have infinite speed None of these 26 / 35 Work function of copper is the order of Electron volt Joule Watt Volt 27 / 35 Work function is the energy needed to Excite an atom Produce X-rays Expel an electron just outside the surface of material To explore an atom 28 / 35 And energy associated with a photon is 10keV. It belongs to X-rays Y-rays Ultraviolet rays Microwaves 29 / 35 Photos are deflected by Magnetic field only Electric field only Electro magnetic field None of the above 30 / 35 How does retarding potential vary with the frequency of light causing photoelectric effect ? Infinite Zero Decreases Increases 31 / 35 Cathode rays behave like - Proton Electron Photon Neutron 32 / 35 The emission of electrons does not occur in which of the following? Photoelectric emission Thermionic emission Secondary emission X-ray emission 33 / 35 What happens to the kinetic energy of the emitted electrons when the light is incident on a metal surface ? It veries with the frequency of light It veries with the light intensity It veries with the speed of light It veries irregularly 34 / 35 The momentum of a particle is doubled. By what factor is wavelength changed ? 1/2 2 3 4 35 / 35 An electron is accelerated by potential drop of V. The De Broglie wavelength will be Ev Itv Mev None of these Your score isThe average score is 0% 0% Restart quiz 0 12th Physics Chapter 12 MCQ Test तैयारी में दम है तो 36 में से 34 सही करके दिखाओं। 1 / 36 The difference between the energy of an excited state and the energy of ground state is called the Ionization energy Excitation energy Both None 2 / 36 The hydrogen uncertainty principle is - Contained in Bohr's model Against Bohr's model Obtained from Bohr's model None of these 3 / 36 The minimum orbital angular momentum of an electron in a hydrogen atom is h h/2 h/2π H 4 / 36 According to the uncertainty principle of an electron time measurement will become uncertain if which of the following is measured with high certainty? Energy Momentum Location Velocity 5 / 36 According to Bohr's curi when electron jumps down from an orbit of higher energy to the third orbit, the spectral lines so emitted are called Balmer series Paschen series Lyman series Pfund series 6 / 36 Which of the following is not charged? Photon Alpha particle Beta particle Electron 7 / 36 The Kinetic energy of the Alpha particle incident on the gold foil is doubled. The distance of closest approach will also be doubled True False 8 / 36 What is the ratio of minimum to maximum wavelength in the balmer series ? 5:9 5:36 1:4 3:4 9 / 36 According to the Rutherford's model of atom was Stable Unstable Semi stable None of these 10 / 36 Which of the following did bohr use to explain his theory ? Quantization of angular momentum Conservation of an Quantum frequency Conservation of mass Conservation of linear momentum 11 / 36 The bohr model of atoms uses Einstein's photoelectric equation. True False 12 / 36 The helium atom does not contain - Two protons Two neutrons Two electrons Six nucleons 13 / 36 The Rutherford's experiment confirm that Coulomb's law holds for atomic dimensions Coulomb's law does not hold for atomic dimensions Ampere circuital law hold for atomic dimensions None of these 14 / 36 Which of the following series of the hydrogen spectrum lies wholly in ultraviolet region? Lyman series Balmer series Paschen series None of these 15 / 36 The binding energy of the hydrogen atom is Infinite Zero 1 -13.6eV 16 / 36 What did ratherford Alpha particle experiment prove? Electron Protons Neutrons Nucleus 17 / 36 Electrons in the atoms are held due to Nuclear forces Gravitational forces Coulomb's forces None of these 18 / 36 The electrons of Rutherford's model would be expected to lose energy because They jump on the nucleus They move randomly Radiate electromagnetic waves Escape from the atom 19 / 36 The significant result deduced from Rutherford's scattering experiment is that The whole of the positive charge is concentrated at the centre of an atom There are neutron inside the nucleus Alpha particles are hydrogen nuclei Electrons are embedded in the atom 20 / 36 The work done that must be done to remove an electron from an atom is called Excitation energy Ionisation energy Both None 21 / 36 The experiment that supported Bohr's idea that there are discrete energy levels in atoms and the process of photon emission, was Frank-Hertz experiment Rutherford scattering experiment Davisson-German experiment None of these 22 / 36 Which series of hydrogen spectrum does not lie in infrared region? Humphreys series Pfund series Brackett series Lyman series 23 / 36 Why was Rutherford's atomic model unstable? Electrons do not remain in orbit Nuclei will breakdown The nucleus repels electrons Orbiting electrons radiate energy 24 / 36 What is the valence electron in alkali metal? F electron P electron S electron D electron 25 / 36 All energy States above the ground state are called Stationery state Excited state Both None 26 / 36 Who discovered the first spectral series? Lyman Balmer Paschen Pfund 27 / 36 Electrons in the atoms are held to the nucleus by Nuclear force Coulomb's force Gravitational force None of these 28 / 36 If an Alpha particle collides head on with a nucleus, what is its impact parameter ? Zero Infinite 1 17 29 / 36 Which of the following series of hydrogen spectrum is in visible range? Lyman series Balmer series Paschen series Brackett series 30 / 36 Which source is associated with a line emission spectrum? Electric fire Neon street sign Red traffic light Sun 31 / 36 The Rutherford's scattering experiment discovered the existence of Negatively charged nucleus Positively charged nucleus Neutrons in nucleus Equipartition of positive charge in atom 32 / 36 Which of Bohr's result for H-atom is experimently wrong? Ground state energy is 13.6eV Ionization potential is 13.6V Explain energy spectrum Ground state angular momentum is h/2π 33 / 36 According to the classical theory, the circular path of the electrons is Circular Parabolic Spiral Straight line 34 / 36 According to the Rutherford's model of atom was Stable Unstable Semi stable None of these 35 / 36 Which one is not divisible? Atom Nucleus Photon None of these 36 / 36 Hydrogen atoms are excited from ground state to the state of principal quantum number 4. Then what will be the number of spectral lines observed? 3 6 5 2 Your score isThe average score is 0% 0% Restart quiz 0 12th Physics Chapter 13 MCQ Test तैयारी में दम है तो 36 में से 34 सही करके दिखाओं। 1 / 36 Which particle must be emitted with beta particle from nucleus? Proton Neutrino Neutron None of these 2 / 36 Life of a fossil in estimated by Carbon dating X-rays Laser Y-rays 3 / 36 The values of N/Z for stable nuclei are : 1-1.6 1.6-2.0 3.0-4.0 4.0 4 / 36 Two nuclei of isobars of an element must have Equal number of neutrons Equal number of protons Equal mass numbers Unico number of protons 5 / 36 First nuclear reaction has been done by Chadwick Einstein Pauli Rutherford 6 / 36 The number of neutrons in nucleus is - A+Z A-Z Z+A/2 Z 7 / 36 X-rays are emitted in Beta Alpha Electron capture None of these 8 / 36 Two nuclei of isobars of an element must have Equal number of neutrons Equal number of protons Equal mass numbers Unico number of protons 9 / 36 Which of the following mass number related to Alpha activity ? 1 100 180 212 10 / 36 The specific binding energy of nucleus is ____then binding energy . Greater Smaller Lowest None of these 11 / 36 The constituents of nucleus are Electrons and protons Protons and neutrons Neutrons and electrons Electrons protons and neutrons 12 / 36 The radius of a nucleus is Directly proportional to its mass number Inversely proportional to its atomic weight Directly proportional to the cube root of its mass number None of these 13 / 36 Atomic number decreases with the emission of Alpha particles from the nucleus by 1 2 3 4 14 / 36 Beta rays are deflected in Gravitational field Only in a magnetic field Only in electric field Both in magnetic and electric fields 15 / 36 The usual constituents of a nucleus are Protons Protons and neutrons Alpha particles Protons and electrons 16 / 36 The time in which radioactive substance became half of its initial amount is called Average life Half Life Time period Decay constant 17 / 36 Beta rays are fast moving Photons Protons Electrons Neutron 18 / 36 Mass defect per nucleon is called Packing fraction Energy defect Momentum defect None of these 19 / 36 Which of the relations is correct for radioactive atom? Half life = average life Half life = 2× average life Half life = 1.6931× average life Half life = 0.6931× average life 20 / 36 The half life of radioactive nucleus is 20h. What fraction of original its activity Be just after 40h? 1/4 1/8 1/2 1/16 21 / 36 The mean life of a radioactive substance is 100 years. It's half life will be 50 years 100/2 ×0.06 years 69.3 years None of these 22 / 36 X rays was discovered by Becqueral Marie Curie Roengton Vanlaw 23 / 36 The unit of radioactivity is Me Curie AMU Joule 24 / 36 The nucleus of any atom is made up of Proton Proton and electron Alpha particle Proton and neutron 25 / 36 Which of the following is correct for Alpha particle? Electron Electromagnetic radiation Helium nucleus Hydrogen nucleus 26 / 36 Gamma rays are similar to Alpha rays Beta rays Cathode rays X-rays 27 / 36 The source of solar energy is Nuclear fission Chemical reaction Annihilation of elementary particles Nuclear fusion 28 / 36 Which one of the following has maximum penetrating power ? X-rays Cathode rays Alpha rays Gamma rays 29 / 36 Which of the following is not a fundamental particle? Neutron Proton Alpha particle Electron 30 / 36 To isotopes of an element have equal number of- Equal number of neutrons Equal number of protons Equal number of protons and neutrons None of these 31 / 36 The reason for high penetrating power of Gamma rays is Short wavelength Long wavelength Absence of charge Both a and c 32 / 36 The quantities, which remain conserved in a nuclear reaction - Total charge Angular momentum Linear momentum All of the above 33 / 36 In nuclear reactors, the control rods are made of Cadmium Graphite Krypton Plutonium 34 / 36 The half Life period of a radioactive isotope is 5 years. After 15 years the fraction decayed will be 1 1/8 7/8 5/8 35 / 36 What is the unit of radioactivity? Joule Mev amu Curie 36 / 36 The function of moderator in nuclear reactor is to Slow the speed of neutrons Fast the speed of neutrons Slow the speed of electrons Fast the speed of electrons Your score isThe average score is 0% 0% Restart quiz 0 12th Physics Chapter 14 MCQ Test तैयारी में दम है तो 36 में से 34 सही करके दिखाओं। 1 / 35 The impurity element used for p type semiconductor is Boron Bismuth Arsenic Phosphorus 2 / 35 At zero degree Kelvin the piece of germanium Is semiconductor Is good conductor Is bad conductor Keeps maximum conductivity 3 / 35 In full wave rectification if input frequency is 50 Hz then output frequency will be- 50HZ 100HZ 2HZ 20HZ 4 / 35 When LED is reserved biased, Light is not emitted Light is emitted Light is not even abserved None 5 / 35 In a transistor ,the majority charge carries are communicated towards the base by the part Emitter Base Collector None 6 / 35 For NPN transistor is common base beta is 100 the current gain Alpha for common emitter will be 0.99 1.01 0.9 0.98 7 / 35 Junction transistor with back to back on junction was discovered by J.Barden W.H brattain Both W schockely 8 / 35 Which one of the following logic gates is universal logic gate ? OR AND NOT NAND 9 / 35 Transistor can act as a switch in Saturation mode Cut off mode Both None 10 / 35 Which configuration of transistor has highest voltage gain ? Common base Common emitter Common collector None 11 / 35 Diode maybe used to Change AC into DC Change DC into AC As an amplifier None 12 / 35 In N type semiconductors , majority charge carriers are Protons Holes Alpha particles Electrons 13 / 35 (1+1) in binary addition is 1 0 10 100 14 / 35 The group third element used asants for germanium and silicon gives us Insulator N type semiconductor P type semiconductor None 15 / 35 Full wave rectifier uses Two diodes Three diodes Four diodes Five diodes 16 / 35 For obtaining p type semiconductor travelent material is mixed in germanium but for obtaining and type semiconductor which is fixed with ge- Tetravalent Pentavalent Trivalent None 17 / 35 To obtain an oscillator from an amplifier the type of feedback used is Positive Negative Sometimes positive and sometimes negative None 18 / 35 The device to convert solar energy into electrical energy is Solar cell Dry cell Accumulator Botton cell 19 / 35 For semiconductors the gap between valence and conduction energy bands is Wide band gap Narrow band gap Band gap that is neither norwide None of these 20 / 35 A P-type semiconductor is Positively charge Negatively charge Uncharged Absolute zero 21 / 35 The gap between conduction energy band and valence energy band is called Forbidden energy gap Band gap Valence band Conduction band 22 / 35 The minority current carry in p type semiconductor are Electrons Holes Photon Protons 23 / 35 Main gate (basic gate) is- AND ,OR OR ,NOT NAND , OR AND , OR , NOT 24 / 35 With the increase of temperature, the resistance of a semiconductor Increases Decreases Sometimes increases and sometimes decreases Remains unchanged 25 / 35 The impurity to get p type germanium or silicon semi conductor should be Trivalent Tetravalent Pentavalent None 26 / 35 The temperature coefficient of a semiconductor is Positive Negative Zero Infinity 27 / 35 For P-N-P transistor with common base , the value of Alpha is 0.98 , then common emitter current hain beta will be 5 2 89 49 28 / 35 In binary system 111 represent 1 7 3 100 29 / 35 Width of forbidden band is maximum for Metals Semiconductors Insulators None of these 30 / 35 The Boolean expression for AND gate is A+B A Y=A.B None 31 / 35 A semi conductor is cooled from T1K to T2K , then its resistance will- Increase Decrease Remains constant First decrease then increase 32 / 35 Majority carries in p type semiconductors are Electrons Holes Photons Protons 33 / 35 Which of the following is the Boolean expression of OR gates A+B=Y A.B=Y A+B A-B 34 / 35 Unit of amplification factor of transistor is Volt Ampere Ohm No unit 35 / 35 Diode is used as Amplifier Oscillator Modulator Rectifier Your score isThe average score is 0% 0% Restart quiz 1 12th Physics Chapter 15 MCQ Test तैयारी में दम है तो 34 में से 32 सही करके दिखाओं। 1 / 34 For long distance radio broadcast mainly used means is Ground wave Visible wave Ionospheric reflection None of this 2 / 34 Radar system uses Microwave Radiowave Infrared None 3 / 34 The maximum electron density of the inosphere on a day is directly proportional to Critical frequency Square of critical frequency Both None 4 / 34 Waves of UHf frequency are generally transmitted as Ground waves Sky waves Surface waves Space waves 5 / 34 Range of UHf is 300MHz to 3000MHz 9272636 Mhz917 300khz 6 / 34 The communication suited to frequency about 40 mhz is by Ionosphere Satellite Ground wave None of these 7 / 34 Which is not an example of digital communication? Email Cellular phone Television network Satellite communication 8 / 34 Space wave propagation , used in TV has a frequency range of 40MHz or more 10MHz 1MHz None 9 / 34 Modulation is of 2 types 3 types 4 types 5 types 10 / 34 Laser action needs High temperature Semiconductor High pressure Number inversion 11 / 34 Which frequency range is used for TV transmission? 2 70 30MHz-300MHz 30GZ-47Hz 12 / 34 Superimposing information single on carreir wave is called Transmission Modulation Demodulation Reception 13 / 34 Information in AM wave is contained in Carrier only Carrier wave Only in side bands Only in high side bands 14 / 34 The height of geostationary Satellite from the ground is 725525km 35930km 6244482km 2579996km 15 / 34 Range of microwaves is 2MHz 4Mhz 30kz-400kz 30MHz-300MHz 16 / 34 In amplitude modulation- Amplitude is kept constant Frequency is according to modulated voltage Amplitude changes according to modulating voltage Amplitude changes according to modulating frequency 17 / 34 On a particular day the maximum frequency reflected from the ionosphere is 10 mhz on other day it was found to increase to 11mhz .the ratio of maximum electron density of the ionosphere on the two days density of ionosphere on the two days is 1.21:1 12 6 None 18 / 34 Meaning of FAX is - Full access transmission Facsimile telegraphy Factual auto access Feed auto exchange 19 / 34 In frequency modulation the single affects - Amplitude Frequency Both a and b None 20 / 34 The device given intense monochromatic parallel and highly coherent light beam is Laser Radar TV Computer 21 / 34 Sky wave communication is based upon- Reflection by ionosphere Absorption by ionosphere Transmission through Ionosphere None 22 / 34 On a particular day the maximum frequency related from the ionosphere is 10 mhz on the other day it was found to decrease to 8 mhz . what is the ratio of the maximum density of ionosphere on the 2 days 4:5 16:25 2:1 None 23 / 34 WWW is acronym for World wide wire World wide web World wide wise None 24 / 34 The height of a tv transmission Tower at any place on the surface of the Earth is 245 m. the maximum distance up to which transmission of Tower will reach is 245 m 245 km 56 km 128 km 25 / 34 The values possible in digital single are 0&1 All the values All the values between zero and one None 26 / 34 Which range of frequency is used in TV transmission? 30HZ-300HZ 30KHZ 30MHz-300MHz 0 27 / 34 Which of the following units is correct to measure attenuation? Decibel Ohm Amphere Volt 28 / 34 In pulse modulation- Height of pulse is affected Width of pulse is modulated Pulse position is modulated All of these 29 / 34 Radio wave are reflected by- Inosphere Stratosphere Tropodhy None 30 / 34 GPS is acronym for Global positioning system Global positioning of satellite Gross product of sugar None 31 / 34 What is the meaning of BER Bit efficiency ratio Bit error ratio Brand efficiency ratio Bit error rate 32 / 34 Analogue communication may be related to - Amplitude modulation Frequency modulation Phase modulation All of these 33 / 34 Unit of information is Bit Hertz Watt None 34 / 34 Digital single comprise of One bit words Fore bit words or their multiples Two bit word or their multiples None Your score isThe average score is 44% 0% Restart quiz
