Question 1

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

Accepted Answer

The total electric charge in any closed system remains constant over time.

Question 2

A neutral lithium atom has 3 protons, 4 neutrons, and 3 electrons. If it loses one electron, what type of ion does it become?

Accepted Answer

A positive ion

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

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

Question 4

What is the direction of the electric field produced by a positive point charge?

Accepted Answer

It points away from the charge.

Question 5

A negatively charged plastic rod is brought near a metal ball supported by an insulating stand. What happens to the electrons in the metal ball?

Accepted Answer

They are repelled and move away from the rod.

Question 6

Which of the following best describes the process of charging by induction?

Accepted Answer

A charged object is brought near a conductor, causing a redistribution of charges without direct contact.

Question 7

What is the effect called when a charged comb attracts small bits of neutral paper?

Accepted Answer

Polarization

Question 8

Which statement about electric field lines is correct?

Accepted Answer

Electric field lines never intersect.

Question 9

Given two equal positive charges, what is true about the electric field lines between them?

Accepted Answer

The field lines curve away from each other and never intersect.

Question 10

Which formula gives the electric field $$\vec{E} at a $$distance $$r$$ from a point charge $$q$$?

Accepted Answer

$$\vec{E} = \frac{1}{4 \pi \$$varepsilon_0$$} \frac{q}{r^2$} \hat{r}$$

Question 11

A water molecule is electrically neutral but acts as an electric dipole. What causes this dipole moment?

Accepted Answer

Displacement of charge due to chemical bonds within the molecule.

Question 12

What happens when a dipole is placed in a uniform electric field?

Accepted Answer

There is a net torque but no net force on the dipole.

Question 13

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

Accepted Answer

Copper

Question 14

If a metal ball is negatively charged, what will happen when it is brought near a positively charged glass rod?

Accepted Answer

The ball will be attracted to the glass rod.

Question 15

Which of the following best describes the superposition principle for electric fields?

Accepted Answer

The total electric field at a point is the vector sum of the fields due to all charges present.

Question 16

Which of the following is true about the magnitude of the electric field produced by a point charge as the distance from the charge increases?

Accepted Answer

The field strength decreases with increasing distance.

Question 17

What is the force $$\vec{F} on a $$test charge $$q_0$$ placed in an electric field $$\vec{E}$$?

Accepted Answer

$$\vec{F} = q_0$ \vec{E}$$

Question 18

In electrostatic painting, why do negatively charged paint droplets stick to a metal object?

Accepted Answer

The metal object is induced with a positive charge, attracting the negative droplets.

Question 19

Which of the following statements about electric field lines of a dipole is correct?

Accepted Answer

Field lines point away from positive charges and toward negative charges.

Question 20

A comb is run through hair and then used to pick up small bits of paper. What is the best explanation for this phenomenon?

Accepted Answer

The comb becomes charged and polarizes the molecules in the paper, resulting in attraction.

Chapter 21: Electric Charge and Electric Field – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards