P4.1.2 - Currents and Fields

Question 1

Who and when was it discovered that there is a magnetic field around a wire that is carrying charge?

Answer 1

Hans Christian Oersted in 1820

Question 2

What else did Oersted discover?

Answer 2

That if the current was coming towards you, the field lines were anti-clockwise

Question 3

What does the strength of the field around a wire depend on?

Answer 3

The magnitude of the current and the distance from the wire

Question 4

What is the strength of a magnetic field measured in?

Answer 4

Teslas(T)

Question 5

What is the strength of the Earth’s magnetic field?

Answer 5

0.01mT

Question 6

What is the strength of the field cm from a wire carrying a current of 5A

Answer 6

0.1mT

Question 7

What is a solenoid?

Answer 7

Many parallel loops of wire making a coil

Question 8

What happens to the magnetic fields in a solenoid?

Answer 8

They add up making a much stronger field

Question 9

How could you create an induced magnet?

Answer 9

You could put a magnetic material inside the core

Question 10

How strong are the electromagnets in MRI scanners?

Answer 10

10T