Q: The electric potential energy $$U_{\text{elec}} of $$two point charges $$q_1$$ and $$q_2$$ separated by a distance $$r is $$given by:

$$U_{\text{elec}} = \dfrac{q_1$ q_2$}{4 \pi \$$varepsilon_0$$ r}$$

Q: The change in potential energy $$\Delta U$$ for a conservative force is related to the work done by the force by:

$$\Delta U = -W_{\text{interaction}}$$

Question 1

Which of the following best describes electric potential energy?

Accepted Answer

It is the interaction energy between charged particles due to the electric force.

Question 2

The electric potential $$V at a $$point in space is:

Accepted Answer

A scalar quantity that exists everywhere in space.

Question 3

Which of the following is true about equipotential surfaces?

Accepted Answer

They are mathematical surfaces with the same value of potential $$V at $$every point.

Question 4

The electric potential energy $$U_{	ext{elec}} of $$two point charges $$q_1$$ and $$q_2$$ separated by a distance $$r is $$given by:

Accepted Answer

$$U_{	ext{elec}} = \dfrac{q_1$ q_2$}{4 \pi \$$varepsilon_0$$ r}$$

Question 5

What are the units of electric potential difference?

Accepted Answer

Volts

Question 6

A positive charge is released from rest in a uniform electric field. What happens to its kinetic energy as it moves toward the negative plate?

Accepted Answer

It increases.

Question 7

The electric potential inside a parallel-plate capacitor:

Accepted Answer

Increases linearly from the negative to the positive plate.

Question 8

Which of the following is a correct expression for the work done by a constant force $$\vec{F}$$ over a displacement $$\Delta \vec{r} at an $$angle $$	heta$$?

Accepted Answer

$$W = F \Delta r \cos 	heta$$

Question 9

If the electric field between two parallel plates is $$E$$ and the distance between the plates is $$d$$, what is the potential difference $$\Delta V$$ between the plates?

Accepted Answer

$$\Delta V = Ed$$

Question 10

A proton is released from rest at the surface of a positively charged sphere. As it moves away from the sphere, what happens to its electric potential energy and kinetic energy?

Accepted Answer

Potential energy decreases, kinetic energy increases.

Question 11

Which of the following statements about the electric potential of a point charge $$q is $$correct?

Accepted Answer

It decreases inversely with distance from the charge.

Question 12

In a uniform electric field, a negative charge moves in the direction of the field. What happens to its potential energy?

Accepted Answer

It increases (becomes less negative).

Question 13

The electric field $$\vec{E} is $$related to the electric potential $$V by $$which of the following expressions?

Accepted Answer

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

Question 14

A system consists of two like charges. As they move closer together, what happens to the total mechanical energy if only conservative forces are present?

Accepted Answer

It remains constant.

Question 15

Which of the following is a property of equipotential surfaces?

Accepted Answer

The electric field is always perpendicular to the surface.

Question 16

If a positive charge is released from rest, it will move in the direction of:

Accepted Answer

Lower electric potential.

Question 17

The change in potential energy $$\Delta U$$ for a conservative force is related to the work done by the force by:

Accepted Answer

$$\Delta U = -W_{	ext{interaction}}$$

Question 18

A charged particle $$q$$ moves through a potential difference $$\Delta V. $$The change in its kinetic energy is:

Accepted Answer

$$q \Delta V$$

Question 19

Which of the following is true for the electric potential energy of two opposite charges as they move closer together?

Accepted Answer

It becomes less negative (increases in magnitude).

Electric Potential and Potential Energy: Concepts, Calculations, and Applications

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