MCQs of Electrostatic Potential and Capacitance

Electrostatic Potential and Capacitance MCQs

MCQs of Electrostatic Potential and Capacitance

Showing 51 to 60 out of 141 Questions

51.

In the region between a charged plate of parallel plate capacitor and a dielectric, the electric field becomes 1000 V/m and after that battery is removed and a dielectric slab of thickness of 0.4 cm and dielectric of dielectric constant 4.0 is introduced between them, then,

(a)What is the electric field in the dielectric ?

(b)What is the potential difference between two plates after the dielectric is introduced ?

The electric field between the plates and dielectric is 10⁴ V/m.

(a)	25 x 10^-2 V/m, 70V
(b)	25 x 10² V/m, 70V
(c)	25 x 10² V/m, 7V
(d)	25 x 10⁴ V/m, 7V

52.

A substance has a dielectric constant 2.0 and its dielectric strength is 20 x 10⁶ V/m. It is taken as a dielectric material in a parallel plate capacitor. The minimum area of its each plate such that its capacitance becomes 8.85 x 10^-2 μF and it can withstand a potential difference of 2000 V is _____

(a)	0.2 m²
(b)	0.3 m²
(c)	0.4 m²
(d)	0.5 m²

53.

Two identical thin rings each of radius R m are kept on the same axis at a distance of R m apart. If charges on them are Q₁C and Q₂C respectively, the work done in moving a charge qC from the centre of one ring to that of the other is _____

(a)	$\frac{q (Q_{1} - Q_{2})}{4 {πξ}_{0} R} (\frac{1 - \sqrt{2}}{\sqrt{2}})$
(b)	$\frac{q (Q_{2} - Q_{1})}{4 {πξ}_{0} R} (\frac{\sqrt{2} - 1}{\sqrt{2}})$
(c)	$\frac{q (Q_{1} - Q_{2})}{4 {πξ}_{0} R} (\frac{\sqrt{2} - 1}{\sqrt{2}})$
(d)	$\frac{q (Q_{1} - Q_{2})}{4 {πξ}_{0} R} (\frac{\sqrt{2}}{\sqrt{2} - 1})$

54.

q₁ = 2C and q₂ = -3 charges are placed at (0, 0) and (100, 0)m points respectively. At which point(s) on the X-axis is the electric potential zero ?

(a)	40 m, 200 m
(b)	-40 m, 200 m
(c)	40 m, -200 m
(d)	-40 m, - 200 m

55.

In a certain region, the electric potential is given by the formula V(x, y, z) = 2x²y+3y³z-4z⁴x. Find the components of electric field and the vector electric field at point (1, 1, 1) in this field.

(a)	(-11, 0, 13), $\vec{E} = - 11 \hat{i} + 13 \hat{k}$
(b)	(0, 11, -13), $\vec{E} = - 11 \hat{j} - 13 \hat{k}$
(c)	(0, 11, 13), $\vec{E} = - 11 \hat{j} - 13 \hat{k}$
(d)	(0, -11, 13), $\vec{E} = - 11 \hat{j} - 13 \hat{k}$

56.

A spherical drop of water has 3 x 10^-10C amount of charge residing on it. 500 V electric potential exists on its surface. Calculate the radius of this drop. If eight such drops (having identical charge and radii) combine to form a single drop, calculate the electric potential on the surface of the new drops. (k = 9 x 10⁹ SI)

(a)	0.054 cm, 2000V
(b)	0.54 cm, 2000V
(c)	0.0054 cm, 2000V
(d)	0.54 cm, 20V

57.

Q amount of electric charge is present on the surface of a sphere having radius R. Calculate the total energy of the system.

(a)	$\frac{2 Q^{2}}{k R}$
(b)	$\frac{k Q^{2}}{2 R}$
(c)	$\frac{{RQ}^{2}}{2 k}$
(d)	$\frac{1}{2} \frac{k R}{Q^{2}}$

58.

(1) A capacitor of 900 pF is charged with the help of 100 V battery. Calculate the electric potential energy of this capacitor. (2) The above capacitor is disconnected from the battery and is connected to another identical uncharged capacitor. What will be the total energy of the system ?

(a)	4.5 x 10^-6J, 2.25 x 10^-6J
(b)	2.25 x 10^-6J, 4.5 x 10^-6J
(c)	4.5 x 10⁶J, 2.25 x 10⁶J
(d)	2.25 x 10⁶J, 4.5 x 10⁶J

59.

The distance between two plates of an air filled capacitor is d and capacitance C. It is filled with three different dielectric materials having dielectric constant 2, 3 and 6, then now its capacitance will be _____

(a)	2C
(b)	3C
(c)	5C
(d)	8C

60.

N identical droplets charged to the same potential V are combined to form a single drop. The potential of the new drop will be _____

(a)	V
(b)	$\frac{V}{N}$
(c)	VN
(d)	${VN}^{\frac{2}{3}}$

Showing 51 to 60 out of 141 Questions