Paper 3: Require practical 10 - Magnetic force on a wire

Question 1

What are the safety precautions that should be taken when working with wires carrying high currents?

Answer 1

• Wires carrying the current will get very hot so you shouldn’t touch the wire
• The power supply should be turned off when not required, in order to reduce the heating effect

Question 2

In what direction is the force on the wire due to the magnetic field?

Answer 2

The force on the wire is upwards, but since the wire is clamped in place, a downwards force will be exerted on the mass balance

Question 3

What should the graph look like when plotting the mean mass reading against current?

Answer 3

The graph should be a straight line through the origin, since the mass and current should be directl proportional to each other

Question 4

What length measurements should be used for calculations?

Answer 4

The length of the magnets should be used since this will equal the length of wire that experiences the magnetic field

Question 5

What type of power source must be used in this experiment?

Answer 5

A direct current source must be used so that the current, and therefore the force exerted, is constant and in one direction