Q: A battery has a potential difference of 1.5 V between its terminals. What is the work required to move a charge of $$2\ \mu C$$ from the negative to the positive terminal?

$$3.0 \times 10$$^{-6}$$\ \text{J}$$

Question 1

A positive test charge $$q_0$$ moves from point $$a to $$point $$b in a $$uniform electric field $$\vec{E}$$, as shown in the diagram. If the displacement is $$d$$ and the field is uniform, what is the work done by the electric field?

Accepted Answer

$$W = q_0$ E d$$

Question 2

Which of the following best describes the relationship between electric potential energy and electric potential for a point charge $$q_0 at a $$point with potential $$V$$?

Accepted Answer

$$U = q_0$ V$$

Question 3

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

Accepted Answer

The potential energy increases.

Question 4

The electric potential energy $$U of $$two point charges $$q_1$$ and $$q_2$$ separated by a distance $$r in $$vacuum is given by:

Accepted Answer

$$U = \frac{1}{4\pi\$$epsilon_0$$} \frac{q_1$ q_2$}{r}$$

Question 5

If a positive charge moves opposite to the direction of the electric field, what is true about the work done by the field and the change in potential energy?

Accepted Answer

The field does negative work and the potential energy increases.

Question 6

Which of the following statements about equipotential surfaces is correct?

Accepted Answer

Equipotential surfaces are always perpendicular to electric field lines.

Question 7

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

Accepted Answer

$$V = \frac{1}{4\pi\$$epsilon_0$$} \frac{q}{r}$$

Question 8

A battery has a potential difference of 1.5 V between its terminals. What is the work required to move a charge of $$2\ \mu C$$ from the negative to the positive terminal?

Accepted Answer

$$3.0 	imes 10$$^{-6}$$\ 	ext{J}$$

Question 9

If three point charges $$+q$$, $$+q$$, and $$-q$$ are placed at the vertices of an equilateral triangle, what is the sign of the total electric potential energy of the system?

Accepted Answer

Negative

Question 10

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 11

A conducting sphere of radius $$R$$ carries a charge $$q. $$What is the electric potential at its surface?

Accepted Answer

$$V = \frac{1}{4\pi\$$epsilon_0$$} \frac{q}{R}$$

Question 12

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

Accepted Answer

The electric potential is constant throughout the conductor.

Question 13

A ring of charge produces an electric potential $$V at a $$point on its axis. What is the direction of the electric field at that point?

Accepted Answer

Along the axis of the ring

Question 14

If the electric field at a point is zero, what can you conclude about the electric potential at that point?

Accepted Answer

The electric potential may be nonzero.

Question 15

Where an electric field line crosses an equipotential surface, the angle between the field line and the equipotential is:

Accepted Answer

90°

Question 16

The direction of the electric potential gradient at a certain point is:

Accepted Answer

Opposite to the direction of the electric field at that point.

Question 17

A parallel plate capacitor has plates separated by distance $$d$$ and a potential difference $$V$$ across them. What is the magnitude of the electric field between the plates?

Accepted Answer

$$E = \frac{V}{d}$$

Question 18

A cell membrane has a potential difference across it, with the interior at a lower potential than the exterior. What is the direction of the electric field inside the membrane?

Accepted Answer

From the exterior to the interior

Question 19

If you move a charge $$q$$ from point $$a to $$point $$b in an $$electric field, the change in electric potential energy is given by:

Accepted Answer

$$\Delta U = q (V_b - V_a)$$

Question 20

A sharp lightning rod causes a high electric field at its tip. This is primarily because:

Accepted Answer

The electric field near a sharp point is much greater than near a flat surface for the same potential.

Electric Potential: Concepts, Calculations, and Applications

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