Question 1

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

Accepted Answer

It requires a charged object to be brought near a neutral conductor, causing a redistribution of charges without direct contact.

Question 2

A neutral metal sphere is placed near a negatively charged rod. What happens to the charges in the sphere?

Accepted Answer

Electrons in the sphere are repelled away from the rod, leaving the near side positively charged.

Question 3

Which equation correctly expresses Coulomb’s Law for the magnitude of the electric force between two point charges?

Accepted Answer

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

Question 4

A glass rod is rubbed with silk and becomes positively charged. What happens at the atomic level?

Accepted Answer

Electrons are transferred from the glass rod to the silk.

Question 5

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

Accepted Answer

It points radially outward from the charge.

Question 6

A charged comb can pick up small pieces of paper even though the paper is neutral. What is the best explanation for this phenomenon?

Accepted Answer

The comb induces a polarization of charges within the paper, resulting in an attractive force.

Question 7

Which of the following is true about conductors and insulators?

Accepted Answer

Conductors allow free movement of electric charge, while insulators do not.

Question 8

Which of the following statements about the conservation of electric charge is correct?

Accepted Answer

The algebraic sum of all electric charges in a closed system is constant.

Question 9

A negative ion is formed when:

Accepted Answer

An atom gains electrons.

Question 10

Which of the following best describes the direction of the electric field at a point near a negative point charge?

Accepted Answer

The electric field points toward the charge.

Question 11

If two identical plastic rods are both rubbed with fur and then brought near each other, what will happen?

Accepted Answer

They will repel each other.

Question 12

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

Accepted Answer

The density of field lines indicates the strength of the electric field.

Question 13

A water molecule is a good solvent for ionic compounds because:

Accepted Answer

It is an electric dipole, with partial positive and negative charges at opposite ends.

Question 14

Which of the following is true about the force and torque on an electric dipole in a uniform electric field?

Accepted Answer

There is no net force, but there can be a net torque on the dipole.

Question 15

Which of the following best explains why a charged object can attract a neutral insulator?

Accepted Answer

The charged object induces a polarization of charges within the insulator.

Question 16

Which of the following is a property of electric field lines for a dipole?

Accepted Answer

They start on positive charges and end on negative charges.

Question 17

Which of the following is NOT a consequence of the quantization of electric charge?

Accepted Answer

It is possible to have a charge of $$2.5e on an $$isolated object.

Question 18

Which of the following best describes the result of rubbing a glass rod with silk?

Accepted Answer

The glass rod becomes positively charged and the silk becomes negatively charged.

Question 19

Which of the following is the correct vector equation for the electric field produced by a point charge $$q at a $$distance $$r$$?

Accepted Answer

$$\vec{E} = \frac{1}{4\pi\$$epsilon_0$$} \frac{q}{r^2$} \hat{r}$$

Electric Charge and Electric Field: Fundamental Concepts and Applications

Guida di studio - Domande di pratica