P4.1 - Magnets And Magnetic Fields

Question 1

What is an induced magnet?

Answer 1

A material that is magnetic only when it is placed in a magnetic field.

Question 2

What are domains?

Answer 2

Small magnetic regions in a magnetic substance that have a north and South Pole.
They align when there is an external magnetic field present

Question 3

What does a compass needle line up with?

Answer 3

The magnetic field of the earth towards the magnetic North Pole

Question 4

In Fleming’s left hand rule, what does your thumb, index finger and middle finger represent?

Answer 4

Thumb - force experienced by wire
Index - magnetic field
Middle - current

Question 5

How can you work out the direction of a magnetic field around a current with your hand?

Answer 5

Put your right hand and line it up with the direction of current. They way your fingers are going is the way the magnetic field is

Question 6

What does the magnetic flux density around a wire depend on?

Answer 6

Magnitude of current - bigger current makes a stronger field
Distance from wire - closer to wire makes a stronger field

Question 7

What is the strength of a magnetic field measured in?

Answer 7

Teslas (T)

Question 8

How to make a solenoid?

Answer 8

An iron core and wire coiled into a spiral

Question 9

How can you make a solenoid stronger?

Answer 9

Make more turns in the coil
Place an iron core
Increase the current