Question 1

Which of the following statements best describes the principle of charge quantization?

Accepted Answer

Electric charge exists only in discrete packets, and any charge $$q$$ can be written as $$q = Ne$$, where $$N is an $$integer and $$e = 1.60 	imes 10$$^{-19}$$ C.

Question 2

A glass rod is rubbed with silk, transferring electrons from the rod to the silk. What is the resulting charge on the glass rod?

Accepted Answer

The glass rod becomes positively charged.

Question 3

Which equation correctly expresses Coulomb’s Law for the magnitude of the electric force between two point charges $$q_1$$ and $$q_2$$ separated by a distance $$r$$?

Accepted Answer

$$F = k_e \frac{q_1$ q_2$}{r^2$}$$

Question 4

A point charge $$q$$ generates an electric field at a distance $$r. $$What is the magnitude of this electric field?

Accepted Answer

$$E = k_e \frac{q}{r^2$}$$

Question 5

Which of the following best describes the direction of the electric field generated by a negative point charge?

Accepted Answer

The electric field points toward the charge.

Question 6

Two point charges, $$q_1 = +2$$ \ \mu C$$ and q_2$ = -2 \ \mu C$$, are separated by a distance $$r. $$What is the direction of the force on $$q_1$$ due to $$q_2$$?

Accepted Answer

The force is directed toward $$q_2.$$

Question 7

A parallel-plate capacitor has plates of area $$A$$ and charge $$\pm Q. $$What is the magnitude of the electric field between the plates (assuming vacuum between them)?

Accepted Answer

$$E = \frac{Q}{A \$$epsilon_0$$}$$

Question 8

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

Accepted Answer

The electric field is zero everywhere inside the conductor.

Question 9

A uniformly charged sphere of radius $$R$$ carries a total charge $$Q. $$What is the electric field at a point outside the sphere at a distance $$r \u003e R$$ from the center?

Accepted Answer

$$E = \frac{1}{4 \pi \$$epsilon_0$$} \frac{Q}{r^2$}$$

Question 10

A charged particle of mass $$m$$ and charge $$q is $$placed in a uniform electric field $$\vec{E}. $$What is its acceleration?

Accepted Answer

$$a = \frac{qE}{m}$$

Question 11

Which of the following best describes the electric field lines for a dipole (two equal and opposite charges separated by a small distance)?

Accepted Answer

Field lines start at the positive charge and end at the negative charge.

Question 12

A very large sheet of charge has a uniform surface charge density $$\sigma. $$What is the magnitude of the electric field just outside the sheet?

Accepted Answer

$$E = \frac{\sigma}{2 \$$epsilon_0$$}$$

Question 13

Which of the following is a correct statement about the superposition principle for electric fields?

Accepted Answer

The total electric field at a point is the vector sum of the electric fields produced by each charge.

Question 14

A heart generates a dipole electric field. Which of the following best explains why this is important in medical diagnostics?

Accepted Answer

The dipole field can be detected on the skin, allowing for electrocardiogram (ECG) measurements.

Question 15

A continuous charge distribution has a charge density $$\rho. $$What is the total charge $$Q$$ contained in a volume $$V$$?

Accepted Answer

$$Q = \rho V$$

Question 16

Which of the following is true about the electric field just outside the surface of a conductor in electrostatic equilibrium?

Accepted Answer

The electric field is perpendicular to the surface and has magnitude $$E = \frac{\sigma}{\$$epsilon_0$$}.$$

Question 17

A charged particle is released from rest in a uniform electric field. Which of the following best describes its subsequent motion?

Accepted Answer

It accelerates uniformly in the direction of the electric field if the charge is positive.

Question 18

Which of the following materials is a good conductor of electricity?

Accepted Answer

Copper

Question 19

If the net charge of an electric dipole is zero, why does it still produce an electric field?

Accepted Answer

Because the charges are separated, creating a dipole moment that generates an electric field.

Question 20

Which of the following best describes the relationship between electric force and electric field for a point charge $$q in an $$external electric field $$\vec{E}_{ext}$$?

Accepted Answer

$$\vec{F}_{elec} = q \vec{E}_{ext}$$

Electric Forces and Electric Fields: Structured Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards