S5 Physics - Ch20 Unit Test (Term 2)

Electromagnets are used in _________________ , ________________ and ______________ .

[3 points]

________________ is a switch operated by an electromagnet.

________________ is a coil of wire that becomes magnetised when a current flows through it.

List two ways to reverse the force on a current-carrying conductor in a magnetic field.

[2 points]

List two ways to increase the force on a current-carrying conductor in a magnetic field.

[2 points]

What is the force on a current-carrying conductor that is parallel to a magnetic field?

For Fleming’s left-hand rule, write down the three things that are at 90° to each other, and, next to each one, and write down the finger that represents it.

[6 points]

The diagram shows the circuit diagram and simple construction of an electric bell. Explain how the bell operates.

[5 points]

Describe how the turning effect of a d.c. motor will change if the current flowing through the motor coil is increased.

[2 points]

The diagram shows a relay is being used to switch an electric motor M on and off. Switch S is closed. State what happens to the core.

[1 point]