P7 - Magnetism And Electromagnetism

Question 1

Describe the force that exists between the like poles of two magnets.

Answer 1

A repulsive, non-contact force exists between the like poles of the magnets.

Question 2

Name three magnetic materials.

Answer 2

Iron
Steel
Nickel
Cobalt

Question 3

What can you use to plot the shape and direction of the magnetic field around a straight, current-carrying wire?

Answer 3

A compass (with a pencil and a piece of paper)

Question 4

What can you add to a solenoid to increase its magnetic field strength?

Answer 4

An iron core. (Becomes and induced magnet and increases the magnetic field strength)

Question 5

Why might a current-carrying wire move when placed between magnetic poles?

Answer 5

The magnetic field around the wire interacts with the magnetic field between the poles. This causes the magnet and the wire to exert a force on each other. This force can cause the wire to move.

Question 6

What do the directions of the thumb and first and second fingers indicate in Fleming’s left-hand rule?

Answer 6

Thumb - direction of force / motion
First finger - magnetic field direction
Second finger - current direction

Question 7

Name the effect that causes a coil of current-carrying wire in an electric motor to move.

Answer 7

The motor effect. (The coil in an electric motor is in an external magnetic field. When current flows through the coil, it causes forces to act on parts of the coil)

Question 8

Which rule can be used to work out which way a coil of wire rotated in a motor?

Answer 8

Fleming’s left hand rule