Electromagnetism

Question 1

Magnetic field around a current carrying wire

Answer 1

• Magnetic field is made up of concentric circles (circles which have the same center point)
• Shows that the magnetic field around a wire has no poles
• The further away from the wire, the further apart the circles are: shows the magnetic field is strongest closest to the wire

Question 2

Right hand rule

Answer 2

• Thumb shows direction of current
• Fingers show direction of magnetic field

Question 3

How to reverse direction of magnetic field

Answer 3

• Reverse direction in which current flows

Question 4

What is a conducting wire?

Answer 4

• Any wire that has current flowing through it

Question 5

Magnetic field around a solenoid

Answer 5

• To increase the strength of the magnetic field around a wire, we cant coil it up to form a solenoid
• The magnetic field inside a solenoid is strong and uniform (same strength and direction at any point)
• Magnetic field lines are the same as a bar magnet

Question 6

What is a solenoid?

Answer 6

• When a wire is looped to form lots of coils in one long piece of wire
• An electromagnet (as it has a North and South pole)

Question 7

How can we increase the strength of an electromagnet?

Answer 7

• Increase the current flowing through
• Increase the number of coils by keeping the length the same (coils are more dense)
• Decrease the length while keeping the number of coils the same (coils are more dense)
• Add an iron core (soft magnetic material which will become induced)