# 6.2 Electric Fields Flashcards

Electric Field

A region in which charged bodies will experience a force

What causes an electric field

A charge

How to model a charged sphere

Can be modelled as a point charge when considering outside of the sphere

How electric field lines work

They show the movement of a positive particle. The closer they are the stronger the field.

Basic formula for electric field strength

E = Force per Charge (F/Q)

What is the force between two charges proportional to

The product of their charges,

1 / distance^2

What is the electric field strength proportional to

charge,

1/distance^2

Similarities between an electric and gravitational field in terms of their strength (2)

Both proportional to the value of the charge/mass at a point which is causing the field

Both proportional to 1/r^2

Difference between electric and gravitational fields

Gravitational fields are always attractive whereas electric fields can also be repulsive

Fundamentally what is an electric field

One example of a field giving rise to a force

Equation for electric field strength between to parallel oppositely charged plates

E = V/d

What is special about a uniform electric field

The force/field strength is the same at any point

Motion of a stationary particle when put in a uniform field

Accelerates towards one of the plates depending on its charge

Motion of a particle moving perpendicular to a field that moves into the field

Will continue with same horizontal speed but will accelerate towards one of the plates. Forms a parabola.

Permittivity

Measure of a materials ability to resist an electric field