P7 - Magnetism and Electromagnetism

Question 1

What happens when a current flows through a conducting wire

Answer 1

When a current flows through a conducting wire a magnetic field is produced around the wire.

Question 2

What does the strength of the magnetic field depend on

Answer 2

Current through the wire and the distance from the
wire.

Question 3

What shape is the wire and what does it do

Answer 3

Shaping a wire to form a solenoid increases the strength of the magnetic field created by a current through the wire.

Question 4

Wrapping a wire into a solenoid increases the strength of the magnetic field produced by the current in the wire
Explain why (2 marks)

Answer 4

Field lines around each loop line up
Lots of field lines are close and pointing in same direction

Question 5

Describe the candle wax ball experiment

Answer 5

Place Bunsen burner on heatproof Matt
Use candle wax, stick ball to plates
Leave candle wax to cool
Face back of plates towards flame
Ball that drops first absorbs more infrared

Question 6

Describe how momentum is conserved when a car hits into back of a car (4 marks)

Answer 6

Car has 0 momentum, bus has more
Bus hits car, car moves, car now has momentum
Bus continues to move with smaller velocity
Combined momentum= momentum of the bus before collision