Question 1

Which of the following statements best describes the behavior of electric charges as illustrated in the fourth image (showing force vectors between charges)?

Accepted Answer

Like charges repel each other, and unlike charges attract each other.

Question 2

Based on the third image, which of the following best distinguishes a conductor from an insulator?

Accepted Answer

A conductor allows charge to move freely, while an insulator does not.

Question 3

Refer to the first image. Which subatomic particle is responsible for the negative charge in an atom?

Accepted Answer

Electron

Question 4

A charged rod attracts small pieces of paper, as shown in the second image. What is the best explanation for this phenomenon?

Accepted Answer

The paper is neutral and is attracted due to polarization.

Question 5

According to Coulomb’s law, what is the mathematical expression 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 6

Which of the following best describes the concept of charge conservation?

Accepted Answer

The total charge in an isolated system remains constant.

Question 7

In the fifth image, the linear charge density $$\lambda is $$defined as:

Accepted Answer

$$\lambda = Q / L$$

Question 8

If two point charges are brought twice as close together, how does the magnitude of the electric force between them change?

Accepted Answer

It becomes four times greater.

Question 9

Which of the following is a real-world application of the principles of electric charge and fields?

Accepted Answer

The functioning of a cell phone.

Question 10

A rod of length $$L$$ carries a total charge $$Q$$ distributed uniformly. What is the expression for the charge $$\Delta Q in a $$small segment of length $$\Delta x$$?

Accepted Answer

$$\Delta Q = \lambda \Delta x$$

Question 11

Which of the following statements about electric fields is correct?

Accepted Answer

Electric fields are vectors and can be added using vector addition.

Question 12

A neutral object is brought near a negatively charged rod. What happens to the neutral object?

Accepted Answer

It is attracted to the rod due to induced polarization.

Question 13

Which of the following best describes an electric dipole?

Accepted Answer

Two equal but opposite charges separated by a distance.

Question 14

If the electric field at a point is zero, which of the following must be true?

Accepted Answer

The vector sum of all electric fields at that point is zero.

Question 15

Which equation would you use to calculate the electric field $$E at a $$distance $$r$$ from a point charge $$q$$?

Accepted Answer

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

Question 16

A plastic rod is rubbed with wool and becomes negatively charged. What has happened at the atomic level?

Accepted Answer

Electrons have moved from the wool to the rod.

Question 17

Which of the following best explains why a metal sphere can be charged by contact but a wooden sphere cannot?

Accepted Answer

Metals allow free movement of charge, while wood does not.

Question 18

If a total charge $$Q is $$distributed uniformly over a disk of radius $$R$$, what is the surface charge density $$\sigma$$?

Accepted Answer

$$\sigma = Q / (\pi R^2$)$$

Question 19

Which of the following is NOT a property of electric field lines?

Accepted Answer

They cross each other at right angles.

Electric Fields: Fundamentals and Applications

Study Guide - Practice Questions

Study Guide - Flashcards