P4.1.2 - Currents and fields

Question 1

Any time a current flows in a wire…

Answer 1

A magnetic field is created around it

Question 2

How can the direction of a magnetic field be worked out?

Answer 2

Using ‘‘The Corkscrew Rule’’

Question 3

What is a solenoid?

Answer 3

It is a device that acts to increase the strength/size of the magnetic field around a current carrying wire

Question 4

What are solenoids used to produce?

Answer 4

Electromagnets

Question 5

What is the strength of a magnetic field measured in?

Answer 5

Teslas

Question 6

How can you show there is a field around a solenoid?

Answer 6

You can use iron filings. They will line up near the wire, but not far away from it

Question 7

Describe how you can use a compass to show the magnetic field on a current-carrying wire is larger than the field strength of the earth?

Answer 7

• A compass will naturally align itself with the magnetic field of the Earth
• If a current-carrying wire is brought close to the compass, the needle will move to re align itself with the stronger magnetic field of the wire