Electricity and Circuits

What is the typical alternating potential difference generated by a power station?

• 2500V

• 132000V

• 100kV

• 33kV

Step-up transformers are used to increase the potential difference from 2500V to about _______.

• 100kV

• 33kV

• 132000V

• 230V

What is the purpose of step-down transformers in the National Grid?

• To increase voltage

• To decrease voltage

• To maintain voltage

• To convert AC to DC

Which wire in a plug is connected to the ground at 0 volts?

• Live wire

• Neutral wire

• Earth wire

• Fuse wire

The longest pin of a three-pin plug is designed to make contact with the _______.

• Live wire

• Neutral wire

• Earth wire

• Fuse

What material is commonly used for the pins of a plug because it is a good conductor?

• Copper

• Brass

• Plastic

• Steel

If a live wire touches a neutral wire, what is this called?

• Open circuit

• Short circuit

• Closed circuit

• Ground fault

What happens if too much current passes through the live pin and the live wire?

• The wire cools down

• The fuse blows

• The wire melts

• The circuit opens

Cables used for mains appliances are made of copper because it is a good _______.

• Insulator

• Conductor

• Resistor

• Semiconductor

What is the potential danger if someone touches a live wire?

• They will feel a slight tingle

• They will suffer an electric shock

• Nothing will happen

• The circuit will break