Lực Tương Tác Giữa Hai Điện Tích

What is a point charge?

• An object with very small size.

• A charge considered to be concentrated at a point.

• An object containing very little charge.

• A point that emits charge.

Which statement is correct regarding electric interaction?

• Like charges repel each other.

• Like charges attract each other.

• Opposite charges repel each other.

• Two similar plastic rods, after being rubbed with wool, will attract each other when brought close.

The unit of electric charge is:

• N.

• m.

• C.

• N.m.

Two opposite charges will:

• Attract each other.

• Repel each other.

• Not interact with each other.

• Both attract and repel each other.

Two like charges will:

• Attract each other.

• Repel each other.

• Not interact with each other.

• Both attract and repel each other.

The dielectric constant of air can be considered as:

• ε = 0.

• ε < 0.

• ε > 0.

• ε ≈ 1.

The expression for the force of interaction between two charges in a vacuum is:

• F =

• F =

• F =

• F =

Which statement is false?

• A point charge is a charge considered to be concentrated at a point.

• There are two types of charges: positive and negative.

• Like charges repel each other, opposite charges attract each other.

• When attracting, charges will move closer together.

Which of the following statements about dielectrics is correct?

• A dielectric is a conductive medium. The dielectric constant of a vacuum is 1.

• A dielectric is an insulating medium. The dielectric constant of a vacuum is 1.

• The dielectric constant of a medium indicates how much greater the interaction force between charges in that medium is compared to when they are in a vacuum.

• The dielectric constant can be less than 1.

The magnitude of the force of interaction between two point charges in air:

• Is proportional to the square of the distance between the two charges.

• Is proportional to the distance between the two charges.

• Is inversely proportional to the distance between the two charges.

• Is inversely proportional to the square of the distance between the two charges.