Unit 3 - (Magetism) Motors and The Motor Effect

Question 1

What is the motor effect?

Answer 1

The force experienced by a current-carrying wire in a magnetic field

Question 2

How can the force be increased?

Answer 2

If either the current or themgnetic field is increase

Question 3

How can the force be reversed?

Answer 3

By reversing the magnetic field or the current

Question 4

What happens if the direction of the current or magnetic field is reversed?

Answer 4

The direction of the force is reversed too

Question 5

How can you predict the way the force will act?

Answer 5

by using Flemings left hand rule

Question 6

To experience the full force, what does the wire have to do?

Answer 6

Be at 90° to the magnetic field

Question 7

What happens if the wire runs along parallel to the magnetic field?

Answer 7

It won’t experience any force at all

Question 8

Which finger is for which in flemings left hand rule?

Answer 8

ThuMb - Force (Motion)

First Finger Field (North → South0

SeCond finger - Current (+ → -)

Question 9

How do electric motors use the motor effect?

Answer 9

To get them (and keep them) moving

Question 10

2 factors which speed up an electric motor?

Answer 10

• More current
• Stronger magnetic field

Question 11

What does the split ring commutator do?

Answer 11

It is a way of swapping the contacts every hakf turn to keep the motor rotating in the same direction

Question 12

How can the direction of the motor be reversed?

Answer 12

By either swapping the polarity of the direct current (DC) supply or swapping the magnetic poles over