Question 1

A positive charge $$q_0$$ moves from point A to point B in a uniform electric field $$\vec{E}$$, as shown in the first image. If the displacement between A and B is $$d$$, what is the change in electric potential energy $$\Delta U of $$the charge-field system?

Accepted Answer

$$\Delta U = -q_0$ E d$$

Question 2

In a uniform electric field, a charge $$q_0 is $$moved from point A to point B along a path that makes an angle $$	heta$$ with the direction of the field (see image 2). What is the work done by the electric field?

Accepted Answer

$$W = q_0$ E d \cos 	heta$$

Question 3

A positive charge is released from rest between two parallel plates with a uniform electric field (see image 3). What happens to its kinetic and potential energy as it moves from A to B?

Accepted Answer

Kinetic energy increases, potential energy decreases

Question 4

In a uniform electric field, the work done by the field in moving a charge $$q_0$$ from point a to point b along any path (see image 4) depends on:

Accepted Answer

Only the endpoints a and b

Question 5

A positive charge moves in the direction of the electric field between two plates (see image 5a). What is the effect on its potential energy and the work done by the field?

Accepted Answer

Potential energy decreases, field does positive work

Question 6

A negative charge moves in the direction of the electric field between two plates (see image 6a). What happens to its potential energy?

Accepted Answer

Potential energy increases

Question 7

The electric potential $$V at a $$distance $$r$$ from a point charge $$q is $$given by:

Accepted Answer

$$V = \frac{q}{4\pi\$$epsilon_0$$ r}$$

Question 8

If two point charges $$q_1$$ and $$q_2$$ are separated by a distance $$r$$, what is the electric potential energy $$U of $$the system?

Accepted Answer

$$U = \frac{q_1$ q_2$}{4\pi\$$epsilon_0$$ r}$$

Question 9

Which statement about equipotential surfaces is correct?

Accepted Answer

No work is required to move a charge along an equipotential surface

Question 10

For a charged spherical conductor of radius $$R$$, what is the electric potential at a point outside the sphere ($$r \u003e R$$)?

Accepted Answer

$$V = \frac{q}{4\pi\$$epsilon_0$$ r}$$

Question 11

A cavity is created inside a conductor with no charges inside the cavity. What is the electric field inside the cavity?

Accepted Answer

It is zero everywhere inside the cavity

Question 12

The electric field $$\vec{E}$$ can be found from the electric potential $$V$$ using which relationship?

Accepted Answer

$$\vec{E} = -
abla V$$

Question 13

A Van de Graaff generator is used to accelerate protons. If a proton is accelerated through a potential difference of $$1.0 	imes 10^6$ V, what is the energy gained by the proton in electron-volts?

Accepted Answer

$$1.0 	imes 10^6$ eV

Question 14

In the Millikan oil-drop experiment, what is the purpose of the electric field between the plates?

Accepted Answer

To balance the gravitational force and determine the charge on the droplets

Question 15

Which of the following is true about the electric potential inside a conductor in electrostatic equilibrium?

Accepted Answer

It is constant everywhere

Question 16

A charged particle moves from a point of higher potential to a point of lower potential in an electric field. What happens to its electric potential energy?

Accepted Answer

It decreases

Question 17

The electric potential due to a continuous charge distribution is calculated by:

Accepted Answer

$$V = \int \frac{dq}{4\pi\$$epsilon_0$$ r}$$

Question 18

If two charges $$q_1$$ and $$q_2$$ are brought together from infinity to a distance $$r$$, what is the work required?

Accepted Answer

$$W = \frac{q_1$ q_2$}{4\pi\$$epsilon_0$$ r}$$

Question 19

Which of the following statements about the superposition principle for electric potential is correct?

Accepted Answer

The total potential is the algebraic sum of individual potentials

Chapter 23: Electric Potential – Study Notes

Study Guide - Practice Questions

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