Question 1

Which of the following statements best describes the origin of the word 'electric'?

Accepted Answer

It comes from the Greek word 'elektron', meaning 'amber'.

Question 2

If two objects both have positive electric charges, what will happen when they are brought close together?

Accepted Answer

They will repel each other.

Question 3

Which subatomic particle is responsible for the negative charge in atoms?

Accepted Answer

Electron

Question 4

A neutral atom of lithium has 3 protons, 4 neutrons, and 3 electrons. What is the net charge of this atom?

Accepted Answer

Zero

Question 5

Which of the following statements about electric charge is correct?

Accepted Answer

Electric charge is quantized in units of the electron or proton charge.

Question 6

What is the universal principle of charge conservation?

Accepted Answer

The total electric charge in any closed system is constant.

Question 7

Which material is most likely to be a good conductor of electric charge?

Accepted Answer

Copper

Question 8

When a negatively charged rod is brought near a neutral metal ball without touching it, the ball becomes charged by which process?

Accepted Answer

Induction

Question 9

Which equation correctly expresses Coulomb's law for the magnitude of the 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 10

Two point charges $$q_1 = 25$$\,	ext{nC}$$ and q_2$ = -75\,	ext{nC}$$ are separated by $$r = 3\,	ext{cm}. $$What is the direction of the electric force that $$q_1$$ exerts on $$q_2$$?

Accepted Answer

Toward $$q_1$$

Question 11

A positive test charge is placed in an electric field. In which direction does the force on the test charge point?

Accepted Answer

In the direction of the electric field

Question 12

What is the electric field $$E at a $$point $$P$$ due to a point charge $$q$$ located a distance $$r$$ away?

Accepted Answer

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

Question 13

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

Accepted Answer

Radially inward toward the charge

Question 14

The total electric field at a point due to multiple charges is:

Accepted Answer

The vector sum of the fields from each charge

Question 15

A water molecule is an example of:

Accepted Answer

An electric dipole

Question 16

An electric dipole placed in a uniform electric field experiences:

Accepted Answer

A torque that tends to align the dipole with the field

Question 17

Which of the following is true about the magnitude of the charge of a proton and an electron?

Accepted Answer

Both have the same magnitude of charge but opposite signs.

Question 18

A fish is able to locate prey by sensing weak electric fields. This is an example of:

Accepted Answer

Biological application of electric field detection

Question 19

If an electron is initially moving to the right and enters a uniform electric field directed to the right, which trajectory will the electron follow?

Accepted Answer

It will decelerate and may reverse direction.

Question 20

When you rub a plastic rod with fur, the rod becomes negatively charged and the fur becomes positively charged. What is the best explanation for this?

Accepted Answer

Electrons are transferred from the fur to the rod.

Electric Charge and Electric Field: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards