Answers to AQA GCSE Electromagnetic Circuit Diagrams (Physics)

Practice Question

1.Explain how a scrap yard crane works to be able to pick up and drop scrap iron.

When the crane operator pushes a switch to complete the circuit, current flows through solenoid and an electromagnet is formed. This allows the crane to pick up scrap metal. 

The metal is then moved to a new location. Crane operator pulls the switch to break the circuit, so current stops flowing, solenoid demagnetises. The crane drops scrap iron.

2. Below is a circuit diagram of an electromagnetic lock. Suggest how it works to unlock the door

When the switch is closed a current flows through the coil, a magnetic field forms around the solenoid and an electromagnet forms. This will cause the yellow metal lock to be pulled to the left to unlock the door.

3. Explain how a relay can be used to switch on a larger circuit using a smaller circuit.

When the switch is closed in the circuit below, the circuit on right is complete, current flows through the coil and a magnetic field forms around solenoid. The newly formed electromagnet attracts the iron armature down. 

The iron armature is on a pivot, so as its pulled downwards, the bottom part moves to the left to push the contacts together on the motor circuit. The motor circuit is now complete so the motor will start.

Accordion Content

Accordion Content