Q: A 2.0 nC charge is placed at a point where the electric potential is 500 V. What is the electric potential energy of the charge at this point?

$$U = 1.0 \times 10$$^{-6}$$ \ \mathrm{J}$$

Question 1

A positive test charge is released from rest at a point of high electric potential. What will happen to its electric potential energy and kinetic energy as it moves under the influence of the electric field?

Accepted Answer

Its electric potential energy decreases and kinetic energy increases.

Question 2

Which of the following correctly expresses the relationship between the electric field $$\vec{E}$$ and the electric potential $$V in $$Cartesian coordinates?

Accepted Answer

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

Question 3

A 2.0 nC charge is placed at a point where the electric potential is 500 V. What is the electric potential energy of the charge at this point?

Accepted Answer

$$U = 1.0 	imes 10$$^{-6}$$ \ \mathrm{J}$$

Question 4

Which statement about equipotential surfaces is correct?

Accepted Answer

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

Question 5

The electric potential at a distance $$r$$ from a point charge $$q is $$given by which of the following expressions?

Accepted Answer

$$V = \dfrac{q}{4\pi\$$varepsilon_0$$ r}$$

Question 6

A proton is released from rest in a uniform electric field between two parallel plates. If the potential difference between the plates is 100 V and the distance between them is 0.01 m, what is the magnitude of the electric field?

Accepted Answer

$$E = 10^2$ \ \mathrm{N/C}$$

Question 7

Which of the following best describes the work done by the electric field when moving a charge between two points?

Accepted Answer

It depends only on the potential difference between the points.

Question 8

A solid conducting sphere of radius $$R$$ carries a total charge $$q. $$What is the electric potential at a distance $$r$$ from the center, where $$r \u003c R ($$inside the sphere)?

Accepted Answer

$$V = \dfrac{q}{4\pi\$$varepsilon_0$$ R}$$

Question 9

If the electric potential difference between two points $$a$$ and $$b is$$ $$V_b - V_a = 20 V$$, how much work is done by the electric field in moving a $$2 C $$charge from $$a to$$ $$b$$?

Accepted Answer

$$-40 J$\ (W = q(V_b - V_a))$$

Question 10

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

Accepted Answer

It is constant throughout the conductor.

Question 11

A charge $$q_0$$ moves from point $$a to $$point $$b in an $$electric field $$\vec{E}. $$The potential difference is given by:

Accepted Answer

$$V_b - V_a = -\int_a^b \vec{E} \cdot d\vec{r}$$

Question 12

Which of the following best describes the direction of the electric field relative to equipotential surfaces?

Accepted Answer

Perpendicular to the equipotential surfaces.

Question 13

A particle with charge $$q$$ and mass $$m is $$released from rest at a point where the electric potential is $$V_a$$ and moves to a point where the potential is $$V_b. $$What is its speed at $$V_b$$?

Accepted Answer

$$v = \sqrt{\dfrac{2q(V_a - V_b)}{m}}$$

Question 14

Which of the following is the correct expression for the potential energy of a system of two point charges $$q_1$$ and $$q_2$$ separated by a distance $$r$$?

Accepted Answer

$$U = \dfrac{q_1$ q_2$}{4\pi\$$varepsilon_0$$ r}$$

Question 15

Which of the following is a correct statement about the electron volt (eV)?

Accepted Answer

It is the energy gained by an electron moving through a potential difference of 1 V.

Question 16

A test charge $$q_0 is $$moved in the electric field of a point charge $$q. $$The work done by the field depends on:

Accepted Answer

Only the initial and final positions.

Question 17

Which of the following is true for the potential at the center of a dipole compared to points far away?

Accepted Answer

It is always zero.

Question 18

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

Accepted Answer

$$V = Ed$$

Question 19

A Faraday cage shields its interior from external electric fields because:

Accepted Answer

The electric field inside a conductor is zero in electrostatic equilibrium.

Chapter 23: Electric Potential – Structured Study Notes

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