Electric Charge, Force, and Field

Question 1

Electromagnetic interactions involve particles that have a property called ___ an attribute that is as fundamental as mass.

Answer 1

electric charge

Question 2

states that the algebraic sum of all the electric charges in any closed system is constant.

Answer 2

The universal principle of charge conservation

Question 3

The magnitude of the electron or proton charge is known as

Answer 3

The elementary charge (e)

Question 4

Electric charge is ___; that is, it comes only in discrete amounts.

Answer 4

quantized

Question 5

The SI unit of charge is

Answer 5

the coulomb (C)

Question 6

The ___ of a system is the algebraic sum of its constituent particles.

Answer 6

net charge

Question 7

materials that are perfect conductor

Answer 7

Superconductors

Question 8

When we charge a metal ball using a copper wire and an electrically charge plastic rod. Some of the excess electrons on the rod are transferred from it to the ball, leaving the rod with small number of negative charge.

What is this process called?

Answer 8

Induction

Question 9

The excess of charge during induction is called

Answer 9

Induced Charge

Question 10

True or False: Two neutral insulators can exert electric forces on each other.

Answer 10

TRUE

Question 11

The force between two charges acts along the line joining them, with the magnitude proportional to the product of the charges and inversely proportional to the square of the distance between them.

Answer 11

Coulomb’s Law

Question 12

When calculating the force charge q1 exerts on q2 (F12) using Coulomb’s law, which direction does the unit vector “r hat” point?

Answer 12

From q1 toward q2

regardless of the signs of the charges

Question 13

The electric force obeys the ___, meaning the forces due to individual charges sum vectorially.

Answer 13

superposition principle

Question 14

Consists of a distribution of vectors, one for each point in the region around a charged object, such as a charged rod.

Answer 14

Electric Field (E)

Question 15

The SI unit for the electric field

Answer 15

newton per coulomb (N/C)

Question 16

An electric field is defined as: E = F/q0, where q0 is…

Answer 16

A positive test charge

Question 17

Consists of two point charges of equal magnitude but opposite sign and separated by a distance d.

Answer 17

Electric Dipole

Question 18

___ is directed from the negative end to the positive end of a dipole.

Answer 18

The electric dipole moment (p)

Question 19

When an electric dipole is placed in a region where there is an external electric field, E, electrostatic forces act on the charged ends of the dipole. If the electric field is uniform, what are the directions and magnitudes of the forces?

Answer 19

in opposite directions and with the same magnitude

Question 20

A dipole in an electric field has its ___ potential energy when it is in its equilibrium orientation, which is when its moment p is lined up with the field E.

Answer 20

least