R4RIN – MCQs, Mock Tests | NCERT Class 12 MCQ Questions for Class 12 Physics Chapter 2 Electrostatic Potential and Capacitance

The dimensions of fall of potential per unit distance are given by:

1. [MLT-3 A-1]
2. [ML2T-2A-1]
3. [ML2T-2A-3]
4. [MLT-2A-2]

✅ Correct Answer: 3

Which of the following is blocked by a capacitor ?

1. A.C.
2. D.C.
3. Both A.C. and D.C.
4. Neither A.C. nor D. C

✅ Correct Answer: 2

Two copper spheres of the same radius, one solid and the other hollow, are charged to the same potential. Which will have more charge?

1. Solid sphere
2. Hollow sphere
3. Both will have an equal charge
4. None of the above

✅ Correct Answer: 3

The capacitance of a capacitor will decrease if we introduce a slab of:

1. copper
2. aluminium
3. zinc
4. None of these

✅ Correct Answer: 4

Two capacitors of capacitance 6 µF and 4 µF are put in series across a 120 V battery. What is the potential difference across the 4 µF capacitor ?

1. 72 V
2. 60 V
3. 48 V
4. zero

✅ Correct Answer: 1

In which of the following forms is the energy stored in a capacitor?

1. Charge
2. Potential
3. Capacitance
4. Electric field

✅ Correct Answer: 4

Two conducting spheres of radii r1 and r2 are equally charged. The ratio of their potential is

1. (r1/r2)²
2. (r1r2)²
3. (r1/r2)
4. (r2/r1)

✅ Correct Answer: 2

Twenty seven drops of mercury are charged simultaneously to the same potential of 10 volts. What will be potential if all the charged drops are made to combine to form one large drop ?

1. 180 V
2. 90 V
3. 120 V
4. 45 V

✅ Correct Answer: 2

The P.E. of an electric dipole is maximum when it makes an angle θ with electric field. The value of θ is :

1. π2
2. π
3. zero
4. 3π2

✅ Correct Answer: 2

The amount of work required to increase the distance between -6µC and 4µC from 6 cm to 18 cm will be :

1. 1.8 J (
2. 2.4 J
3. 1.8 µJ
4. 2.4 µJ

✅ Correct Answer: 2

An electron initially at rest is accelerated through a potential difference of one volt. The energy gained by electron is:

1. 1 J
2. 1.6 × 10-19 J
3. 10-19 J
4. None of the above

✅ Correct Answer: 2

A bird sitting on a high power line:

1. gets killed instantly
2. gets a mild shock
3. gets a fatal shock
4. is not affected practically

✅ Correct Answer: 4

Choose the SI unit of electric potential energy :

1. Joule
2. Coulomb
3. Netwon per coulomb
4. Erg

✅ Correct Answer: 1

The capacitance of earth, viewed as a spherical conductor of radius 6408 km is:

1. 1420 µF
2. 712 µF
3. 680 µF
4. 540 µF

✅ Correct Answer: 2

A capacitor is connected to a cell of emf E having some internal resistance r, the potential across the:

1. cell is < E
2. cell is E
3. cell is > E
4. capacitor is E

✅ Correct Answer: 2

If a +ve charge is moved from low to high potential region, the electric potential energy:

1. decreases
2. increases
3. remain the same
4. may increase or decrease

✅ Correct Answer: 2

IA capacitor is connected across a battery and the plate separation of capacitor is increased without removing the battery, then:

1. capacitance will increase
2. charge stored will increase
3. energy stored will decrease
4. potential difference will increase

✅ Correct Answer: 3

Two capacitors of 3 µF and 6 µF are connected in series with a battery of P.d. 12 V. The P.d. across 3µF and 6µF capacitors respectively will be :

1. 8 V, 4 V
2. 6 V, 6 V
3. 4 V, 8 V
4. 9 V, 3 V

✅ Correct Answer: 1

An electric charge of 425 f µC is removed from a fully charged capacitor of capacitance 8.5µF. Its potential will be lowered by:

1. 75 V
2. 100 V
3. 85 V
4. 50 V

✅ Correct Answer: 2

A dielectric is placed in between the two parallel plates of a capacitor as shown in the figure. The dielectric constant of the dielectric being K. If the initial capacity is C, then the new capacity will be:

1. (K + l).C
2. K.C
3. (K+1)2 C
4. (k – l) C

✅ Correct Answer: 3

Minimum number of capacitor of 2µF each required to obtain a capacitance of 5µF will be:

1. 4
2. 3
3. 5
4. 6

✅ Correct Answer: 1

When a dielectric slab is introduced between the plates of a parallel plate capacitor which remains connected to a battery then charge on the plates relative to earlier charge is

1. more
2. less
3. less or may be more
4. same

✅ Correct Answer: 1

Choose the vector physical quantity:

1. Electric flux
2. Electric potential
3. Electric potential energy
4. Electric intensity

✅ Correct Answer: 4

The surface density of charge is measure:

1. Cm-1
2. Cm-2
3. Cm-3
4. JC-1

✅ Correct Answer: 2

A polythene piece rubbed with wool is found to have a negative charge of 6.4 × 10-9c. How many electrons have been transferred during the process?

1. 4 × 1012
2. 4 × 1011
3. 4 × 1010
4. None of the these

✅ Correct Answer: 3

In the above question:

1. no electrons are transferred
2. electrons are transferred from wool to x polythene
3. electrons are transferred from polythene to wool
4. nothing can be decided

✅ Correct Answer: 2

nothing can be decided

1. 3.64 × 1020 kg
2. 4 × 10-28 kg
3. 4 × 1010 kg
4. None of the these

✅ Correct Answer: 1

What is the number of electrons in 100 g water?

1. .35 × 1024
2. 3.35 × 1025
3. 6.02 × 1023
4. None of the above

✅ Correct Answer: 1

A uniform electric field of 10 NC-1 exists in the vertically downward direction. What is the increase in the electric potential asonegoes up through a height of 300 cm ?

1. 15 V
2. 30 V
3. 45V
4. None of the above

✅ Correct Answer: 2

The electric potential of earth is taken as:

1. zero
2. infinity
3. unity
4. None of the above

✅ Correct Answer: 1

A bird sitting on a high power line:

1. gets killed instantly
2. gets a mild shock
3. gets a fatal shock
4. is not affected practically

✅ Correct Answer: 4