# The motor effect

Unit 3

?

## What happens when we place a wire carrying an elec

It will experience a force called the 'motor effect'

1 of 9

## When is this force at a maximum?

When the wire is at an angle of 90 degrees to the magnetic field

2 of 9

## When is the force at 0?

When the wifre is parallel to the magnetic field

3 of 9

## How can the size of the force be increased?

By increasing the strength of the magnetic field

By increasing the size of the current

4 of 9

## When is the direction of force on the wire reverse

If either the direction of the current or the direction of the magnetic field is reversed

5 of 9

## In a simple electric motor, how is the speed of th

By increasing the size of the current

6 of 9

## In an electric motor, how is the direction of the

By reversing the direction of the current

7 of 9

## When current passes through the coil, why does it

Because a force acts on each side of the coil due to the motor effect

Because the force on one side of the coil is in the opposite direction to the force on the other side

8 of 9

## What does the 'split-ring commutator' do? What doe

It reverses the direction of the current around the coil every half turn. This means that because the sides swap over every half-turn, the coil is always pushed in the same direction

9 of 9