Olete.in – MCQs, Mock Tests & Government Job Prep | NCERT Class 12 MCQ Questions for Class 12 Physics Chapter 1 Electric Charges and Field

Which one of the following is the unit of electric field?

1. Coulomb
2. Newton
3. Volt
4. N/C

✅ Correct Answer: 3

Three charges + 3q + q and Q are placed on a st. line with equal separation. In order to maket the net force on q to be zero, the value of Q will be :

1. +3q
2. +2q
3. -3q
4. -4q

✅ Correct Answer: 1

If an electric dipole is kept in a uniform electric field then resultant electric force on it is :

1. always zero
2. never zero
3. depend upon capacity of dipole
4. None

✅ Correct Answer: 1

The number of electron-taken out from a body to produce 1 coulomb of charge will be :

1. 6.25 × 1018
2. 625 × 1018
3. 6.023 × 1023
4. None

✅ Correct Answer: 1

The work done in rotating an electric dipole in an electric field:

1. W = ME (1 – cos θ)
2. W = ME tan θ
3. W = ME sec θ
4. None

✅ Correct Answer: 1

If sphere of bad conductor is given charge then it is distributed on:

1. surface
2. inside the surface
3. only inside the surface
4. None

✅ Correct Answer: 4

Electric field in a cavity of metal:

1. depends upon the surroundings
2. depends upon the size of cavity
3. is always zero
4. is not necessarily zero

✅ Correct Answer: 4

The dielectric constant of a metal is:

1. 0
2. 1
3. ∞
4. -1

✅ Correct Answer: 3

1 coulomb is equal to:

1. 3 × 109 e.s.u.
2. 13 × 109 e.s.u
3. 3 × 1010 e.s.u
4. 13 × 1010 e.s.u.

✅ Correct Answer: 1

Each of the two point charges are doubled and their distance is halved. Force of interaction becomes p times, w here p is :

1. 1
2. 4
3. 116
4. 16

✅ Correct Answer: 4

oulomb’s law in vector form can be written as F⃗ = (14πεn) (q1q2r2)r⃗ where ε0 is the permitivity of free space. The SI units of ε0 will be:

1. N-1m-2C-2
2. Nm-2C2 (
3. N-1m-2C9
4. Nm-2C2

✅ Correct Answer: 3

The dimensional representation of cu will be :

1. [MLT4 A2]
2. [M-1L-3T4A2]
3. [ML-2T ]
4. None of the above

✅ Correct Answer: 1

When placed in a uniform field, a dipole experiences:

1. a net force
2. a torque
3. both a net force and torque
4. neither a net force nor a torque

✅ Correct Answer: 2

A parrot comes and sits on a bare high power line. It will:

1. experience a mild shock ‘
2. experience a strong shock
3. get killed instantaneously
4. not be affected practically

✅ Correct Answer: 3

The SI units of electric dipole moment are:

1. C
2. Cm-1
3. Cm
4. Nm-1

✅ Correct Answer: 3

If two conducting sphere are connected after charging separately then

1. Electrostatic energy sphere energy will remain conserved
2. Electrostatic energy charges remains conserved
3. Electrostatic energy energy and charge remains conserved
4. None

✅ Correct Answer: 2

A soap bubble is given a negative charge, then its radius:

1. increases
2. decreases
3. Remains unchanged
4. may increase or decrease

✅ Correct Answer: 1

A soap bubble is given a negative charge, then its radius:

1. increases
2. decreases
3. Remains unchanged
4. may increase or decrease

✅ Correct Answer: 1

In non-uniform electric field, electric dipole experiences:

1. torque only
2. torque as well as net force
3. force only
4. None of the above

✅ Correct Answer: 2

An electron is sent in an electric field of magnitude 9.1 × 106NC-1. The acceleration produced in it is :

1. 1.6 ms-2
2. 1.6 × 1018ms-2
3. 0.8 × 1018 ms-2
4. 0.8 × 1018 ms-2

✅ Correct Answer: 2

Two point charges +8q and -2q are located at ,v = O and ,v = L respectively. The location of a point on the .v-axis at which the net electric field due to these two point charges b is zero :

1. 4L
2. 8L
3. L/4
4. 2L

✅ Correct Answer: 4

The graph drawn between V are r for a non-conducting charged solid sphere of radius R for r < R will be :

1. straight line
2. parabola
3. hyperbola
4. None of the above

✅ Correct Answer: 4

Corona discharge takes place:

1. at the surface of a conductor
2. near the sharp points of a conductor
3. outside the conductor
4. at the centre of the conductor

✅ Correct Answer: 2

The belt of a Vande Graaf generator gets charge by :

1. corona discharge (b) (c)
2. induction
3. electrification
4. None of the these

✅ Correct Answer: 1

Quantisation of charge implies:

1. Charge does not exist
2. Charge exists on particles
3. There is a minimum permissible magnitude of charge
4. Charge can’t be created

✅ Correct Answer: 3

The conservation of electric charge implies that:

1. Charge can’t be created
2. Charge can’t be destroyed
3. The number of charged particle in the universe is constant
4. Simultaneous creation of equal and opposite charges is permissible

✅ Correct Answer: 4

The number of electrons contained in one coulomb of charge is:

1. 6.25 × 1018
2. 6.25 × 1017
3. 6.25 × 1019
4. 1.6 × 1019

✅ Correct Answer: 1

The unit of intensity of electric field is :

1. metre/volt
2. Joule/newton
3. Coulomb/newton
4. Newton/coulomb

✅ Correct Answer: 1

The unit of intensity of electric field is :

1. metre/volt
2. Joule/newton
3. Coulomb/newton
4. Newton/coulomb

✅ Correct Answer: 1

1 V equals to:

1. 1 J
2. 1 JC-1
3. 1 CJ-1
4. 1 JC

✅ Correct Answer: 2

1 V m-1 equals to:

1. 1 N
2. 1 Mm-1
3. 1 NC-1
4. 1 J-1

✅ Correct Answer: 3

The minimum amount of charge observed so far is:

1. 1 C
2. 4.8 × 1-13 C
3. 1.6 × 10-19 C
4. 1.6 × 1019 C

✅ Correct Answer: 3