Electromagnets - Higher - Edexcel

1

A wire carrying a current in a magnetic field feels a force. What is this effect called?

2

What is the angle between the force and the current flow that feels this force when it is in a magnetic field?

3

What is the unit for ‘magnetic field strength’?

4

Which of these will NOT increase the force on a current-carrying wire in a magnetic field?

5

What happens to the force if the current direction in a magnetic field is reversed?

6

When using Fleming's left-hand rule, what does the thumb represent?

7

0.4 A flows in 0.1 m of wire in a 0.7 T magnetic field. What force acts on the wire?

8

In a dc motor, what is the function of the split ring commutator?

9

Why do the opposite sides of the coil in a dc motor feel forces in opposite directions?

10

In a dc motor the commutator disconnects the current every half turn. Why doesn’t the motor stop?