Question 1

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

Accepted Answer

Electric potential is the electric potential energy of $$q_0$$ divided by its charge.

Question 2

A positive test charge $$q_0$$ moves from point A to point B in the electric field of another positive charge $$q. $$Which statement is correct regarding the electric potential at points A and B?

Accepted Answer

Point A has a higher potential than point B.

Question 3

What is the electric potential at a distance $$r$$ from a point charge $$q$$? (Assume zero reference potential at infinity.)

Accepted Answer

$$V = \frac{kq}{r}$$

Question 4

A $$4.0 	imes 10$$^{-8}$$ C point charge alters the electric potential at a spot 1.2 m away. What is the potential at that spot?

Accepted Answer

$$V = 300 V$$

Question 5

If a negative point charge $$-4.0 	imes 10$$^{-8}$$ C is placed 1.2 m away from a spot, what is the electric potential at that spot?

Accepted Answer

$$V = -300 V$$

Question 6

Two point charges, $$+8.0 	imes 10$$^{-9}$$ C and -8.0$$ 	imes $$10^{-9} C$$, are separated by 0.80 m. What is the electric potential at point A, which is 0.20 m from the positive charge and 0.60 m from the negative charge?

Accepted Answer

$$V = 240 V$$

Question 7

For the same two charges as above, what is the electric potential at point B, which is 0.40 m from each charge?

Accepted Answer

$$V = 0 V$$

Question 8

On the mid-plane between two equal and opposite charges, what is the electric potential?

Accepted Answer

$$V = 0$$

Question 9

Two point charges are fixed in place: $$+2q$$ and $$-q. On $$the line passing through the charges, how many places are there at which the total potential is zero?

Accepted Answer

Two

Question 10

Which statement about equipotential surfaces is correct?

Accepted Answer

The electric field is perpendicular to equipotential surfaces.

Question 11

What is the work done by the electric field when moving a charge $$q_0$$ along an equipotential surface?

Accepted Answer

Zero

Question 12

In equilibrium, what is true about conductors regarding electric potential?

Accepted Answer

Conductors are always equipotential surfaces.

Question 13

The electric field $$E$$ between two parallel plates separated by distance $$d$$ and with potential difference $$V is $$given by:

Accepted Answer

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

Question 14

If the potential difference between two parallel plates is $$-64 V $$and the plates are separated by $$0.032 m$$, what is the electric field between the plates?

Accepted Answer

$$E = 2.0 	imes 10^3$ V/m

Question 15

A test charge $$q_0 is $$moved from plate A to plate B in a parallel-plate capacitor. The work done by the electric field is given by:

Accepted Answer

$$W_{AB} = q_0$ E d$$

Question 16

The potential difference between the plates of a parallel-plate capacitor with charge $$Q$$, plate area $$A$$, and separation $$d is$$:

Accepted Answer

$$\Delta V = -\frac{Qd}{A\$$varepsilon_0$$}$$

Question 17

If the charge on each plate of a parallel-plate capacitor is $$4.0 	imes 10$$^{-9}$$ C, the area is 0.01$ m^2$, and the plates are separated by 1.0$ mm, what is the potential difference between the plates?

Accepted Answer

$$\Delta V = -45 V$$

Question 18

The change in electric potential energy for a charge $$q$$ moving through a potential difference $$\Delta V is$$:

Accepted Answer

$$\Delta EPE = q \Delta V$$

Question 19

An electron is accelerated from rest across a $$+100,000 V $$potential difference. What is the kinetic energy gained by the electron (neglecting gravity)?

Accepted Answer

$$1.6 	imes 10$$^{-14}$$ J

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