Electric Fields

Question 1

Define electric field

Answer 1

An electric field is a region around a charged body where a force is experienced.

Question 2

What is the direction of an electric field at any point in the field?

Answer 2

The direction of an electric field at any point is the direction of the force on a small positive charge placed at that point.

Question 3

What is the direction of an electric field around an isolated positive charge?

Answer 3

away from the positive charge

Question 4

What is the direction of an electric field around an isolated negative charge?

Answer 4

toward the negative charge

Question 5

What is the direction of an electric field between two positive charges?

Answer 5

away from the positive charges

Question 6

What is the direction of an electric field between two negative charges?

Answer 6

toward from the negative charges

Question 7

What is the direction of an electric field between a positive and a negative charge?

Answer 7

from the positive to the negative charge.

Question 8

What is the direction of an electric field between two oppositely charged plates?

Answer 8

From the positive to the negative charge, uniform spacing. Curved at ends.

Question 9

Define electric field strength.

Answer 9

Electric field strength, E at a point in an electric field is the force acting per unit positive charge.

Question 10

What is the relationship between E - electric field strength/ N C^-1, F - Force/N and Q - charge/C?

Answer 10

E = F/Q

Question 11

What is the SI unit of electric field strength?

Answer 11

The SI unit of electric field strength is Newton per coulomb (NC^-1). It is a vector quantity.

Question 12

State Coulomb’s Law.

Answer 12

Coulomb’s Law states that the force experienced when two charged bodies are brought close to each other is proportional to the product of their charges and inversely proportional to the square of the distance between them.

Question 13

What is the formula to calculate the force experienced between two charged bodies.

Answer 13

Force/N
Q1, Q2 - charge/C
E0 - permittivity of free space F m^-1
distance/m

F = Q1Q2/(4TTE0 d^2)

Question 14

Define the permittivity of free space?

Answer 14

The permittivity of free space is as measure of how easy it is for an electric field to be transmitted through space.

Question 15

In the formula for Coulomb’s Law what does a negative value for F indicate?

Answer 15

A negative value for F indicates that the force is attractive.

Question 16

In the formula for Coulomb’s Law what does a positive value for F indicate?

Answer 16

A positive value of F indicate that the force is repulsive.