Ch 2. Electrostatic Potential And Capacitance

Question 1

The value of electric potential at a distance r from a point charge is

Answer 1

Inversely proportional to r

Question 2

If the distance between the two charges is increased, then the electrostatic potential energy of the charges

Answer 2

Decreases

Question 3

64 identical drops each of capacity 5uF combine to form a big drop. What will be the capacity of the big drop?

Answer 3

20 uF

Question 4

Van de Graaff generator is an electrostatic machine which produces

Answer 4

Only high voltage

Question 5

Three capacitors of capacitance 6uF are available. The minimum and maximum capacitances obtained are

Answer 5

2uF, 18uF

Question 6

The net charge on a charged capacitor is

Answer 6

Zero

Question 7

The value of electric potential at a distance r from a point charge q is

Answer 7

1/4πε₀ • q/r

Question 8

Potential gradient is equal to

Answer 8

dV/dx

Question 9

Electric potential is equal to

Answer 9

w/q

Question 10

Two point charges of +10µC and -10µC are placed at a distance 40 cm in air. Potential energy of the system will be

Answer 10

-2.25J

Question 11

The electric potential in equatorial position of an electric dipole is

Answer 11

Zero

Question 12

The electric potential due to a small electric dipole at a large distance r from the centre of dipole is proportional to

Answer 12

1/r²

Question 13

One Farad is equal to

Answer 13

1 CV⁻¹

Question 14

Which of the following is correct for the capacity of a parallel plate capacitor?

Answer 14

ε₀ A/d

Question 15

Equivalent capacity between A and B in figure is

C               C  

A B

Answer 15

C

Question 16

Sum of charges on collecting plate and condensing plate of a charged capacitor is

Answer 16

Zero

Question 17

Two capacitors each of capacity C are connected in parallel. The equivalent capacity is

Answer 17

2C

Question 18

Two capacitors C₁ = 2µF And C₂ = 4µF are connected in series and a potential difference (p.d) of 1200V is applied across it. The potential differences across 2µF will be

Answer 18

800V

Question 19

Three capacitors each of capacity C are connected in series. The resultant capacity will be

Answer 19

C/3

Question 20

The stored energy of a capacitor charge to 100V, is 1J. Capacitance of the capacitor is

Answer 20

2 × 10₋₄ F

Question 21

The equivalent capacity between A and B in the given figure is

      6µF      6µF   A                               B

        6µF

Answer 21

9µF

Question 22

64 identical drops each of capacity 5µF combine to form a big drop.
What is the capacity of big drop?

Answer 22

20µF

Question 23

The equivalent capacity between A and B is

            3µF

A B
2µF 4µF

Answer 23

20/9 µF

Question 24

The equivalent capacity between points A and B is
C
4µF 4µF

4µF 4µF

         2µF

A B

Answer 24

4/3 µF

Question 25

Statement 1 : if a body is negatively charged its mass slightly increases

Statement 2 : To charge a body transfer of electron is done.

Answer 25

Both the statements are true and Statement 2nd is the correct explanation of statement 1st.

Question 26

The charge on plate X and the given figure is?

20V 10V

          Y   X
          C = 2µF

Answer 26

20µC

Question 27

Statement 1 : The capacitance of a capacitor increases with increase in charge on its plate

Statement 2 : V ∝ Q

Answer 27

Both the statements are true and Statement 2nd is the correct explanation of statement 1st.

Question 28

The capacity of any conductor is

Answer 28

C = q/v

Question 29

Energy of a charged conductor is

Answer 29

E = 1/2 CV²

Question 30

If n capacitors of equal capacity C₁ are connected in parallel, the equivalent capacity will be

Answer 30

C = nC₁

Question 31

Dielectric strength for air is

Answer 31

3 × 10⁶ Vm⁻¹

Question 32

Capacity of spherical condenser is

Answer 32

C = 4πε₀ (r R/ r - R)