Class 12 Electric Charges And Fields CBSE Questions & Answers

Class 12 · Electric Charges And Fields

This is Physics Class 12 Electric Charges and Fields CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
which of the following methods can be used to charge a metal sphere positively without touching it . Select the best
  • A
    Rub it with a piece of fur
  • B
    Connect the positive terminal a battery and float the other end of the battery
  • C
    Rub it with a piece of silk
  • D
    Bring a negatively charged rod near the sphere and touch it to ground for a short while
    Correct
2
If \({\rm{1}}{0^{\rm{9}}}\) electrons move out of a body to another body every second, how much time is approximately required to get a total charge of 1 C on the other body?
  • A
    200 years
    Correct
  • B
    220 years
  • C
    120 years
  • D
    180 years
3
Electric charge
  • A
    is a property of protons only
  • B
    is a property of particles such as atoms,ions,electrons etc that defines their behaviour in electrical fields.
    Correct
  • C
    is a property of neutrons onlz
  • D
    is a property of electrons only
4
Electric charges are of
  • A
    3 types
  • B
    2 types
    Correct
  • C
    5 types
  • D
    4 types
5
Conservation of charges in tribo electric charging
  • A
    implies half are positively charged and other half are neutral
  • B
    implies both are positively charged
  • C
    implies one is positively charged and the other is negatively charged.
    Correct
  • D
    implies both are negatively charged
6
Two positive charges
  • A
    repel each other
    Correct
  • B
    attract each other
  • C
    attract each other at times and repel at other times
  • D
    always attract each other
7
Charge is quantized means
  • A
    charges can take on any discontinuous value
  • B
    charges can take on discrete values that are multiples of charge on neutron
  • C
    charges can take on any continuous value
  • D
    charges can take on discrete values that are multiples of charge on electron
    Correct
8
Ionization of a neutral atom is the
  • A
    only gain of one or more neutrons
  • B
    gain or loss of one or more electrons
    Correct
  • C
    only gain of one or more protons
  • D
    only gain of one or more electrons
9
electrostatic force is
  • A
    force exerted by one charge on another when the two are moving in a given frame of reference
  • B
    force exerted by one charge on another when the two are accelerating in a given frame of reference
  • C
    force exerted by an electron on a neutron
  • D
    force exerted by one charge on another when the two are at rest in a given frame of reference
    Correct
10
Conductors are materials
  • A
    that allow movement of neutrons
  • B
    that allow movement of protons
  • C
    that allow movement of electrons
    Correct
  • D
    that allow only random movement of electrons
11
In charging by Induction
  • A
    a metallic object by touching touching with a charged object
  • B
    a metallic object is charged by rubbing it with silk
  • C
    a metallic object is charged by rubbing it with fur
  • D
    a metallic object is charged by bringing a charged object near it
    Correct
12
For charges \({{\rm{q}}_{\rm{1}}}{\rm{and }}{{\rm{q}}_{\rm{2}}}\) separated by a distance R the magnitude of the electrostatic force is given by
  • A
    \(F =\frac{q_1 q_2}{4\pi \epsilon_0 R^3}\)
  • B
    \(F =\frac{q_1 }{4\pi \epsilon_0 R^2}\)
  • C
    \(F =\frac{q_1 q_2}{4\pi \epsilon_0 R^2}\).
    Correct
  • D
    B . \(F =\frac{q_1 q_2}{4\pi \epsilon_0 R}\)
13
The unit of charge is
  • A
    ampere
  • B
    ohm
  • C
    coulomb
    Correct
  • D
    volt
14
Electric field at a point is defined as
  • A
    electric force experienced by two charges at that point
  • B
    electric force per unit charge experienced by a unit charge at that point
    Correct
  • C
    electric force experienced by a dipole at that point
  • D
    electric force experienced by a charge at that point
15
According to superposition of electric fields
  • A
    The electric field of any combination of charges is the vector sum of the individual charges.
  • B
    The electric field of any combination of charges is the vector sum of the fields caused by the individual charges.
    Correct
  • C
    The electric field of any combination of charges is the scalar sum of the fields caused by the individual charges.
  • D
    The electric field of any combination of charges is the cross product of the individual fields.