7.1 - Electric Fields

What is a force field?

A region in which a non-contact force is experienced by an corresponding interacting particle

What is an electric field?

A region in which a charged particle will experience a non-contact force.

What is electric field strength?

The force per unit charge experienced by a charged particle when placed at that point in the field

State the equation used to calculate the force a charge experiences in an electric field.

Force = Electric Field Strength x Charge

F = EQ

What law determines the magnitude of the electric force between two charges?

Coulomb's Law

State Coulomb's law in words.

The force between two charges is directly proportional to the product of their charges and inversely proportional to the square of their separation

Give Coulomb's law in equation form

F = kQq/r²

where k = 1/4πε₀

Describe the electric field pattern around a positive point charge.

A radial field, acting outwards.

Describe the electric field pattern around a negative point charge.

A radial field, acting inwards.

Describe the uniform electric field between parallel plates.

What equation is used to calculate the electric field between parallel plates?

E = V/d

What is electric potential?

The amount of energy required to move a positive test charge from infinity to a given point in an electric field.

How do you calculate electric potential for a radial field?

F = kQ/r

where k = 1/4πε₀

What are equipotentials?

Equipotentials are lines along which the electric potential remains the same

How do you calculate the work done in moving a charge along an equipotential?

No work is done when moving a charge along an equipotential since the electric potential doesn't change