science revision 23/24

Why should a temporary earth bond be fitted before cutting into any metallic pipework?

• To prevent water leakage

• To maintain the earth continuity

• To measure the pipe's diameter

• To check the water pressure

How long should the clamps of a temporary earth bond be left in place?

• Until the pipework is replaced

• Until the pipework is tested for leaks

• Until the permanent electrical continuity is re-established

• Until the temporary earth bond is no longer needed

What must all circuits and appliances be protected by according to modern regulations?

• An RCD only

• A fuse or MCB

• A fuse or MCB and an RCD

• Isolation switch

Where is permanent de-commissioning done?

• At the appliance

• At the consumer unit

• At the main switch

• At the circuit breaker

What is required for every circuit and appliance for safety?

Where can temporary de-commissioning be done?

• At the consumer unit

• At the main switch

• At the appliance

• At the circuit breaker

What does the symbol with a straight line on top of a dashed line represent in electrical diagrams?

• AC symbol

• Ground connection

• DC symbol for rectified current

• DC symbol for battery

What does the symbol with a sine wave inside a circle represent in electrical diagrams?

• AC symbol

• DC symbol for rectified current

• DC symbol for battery

• Ground connection

Which symbol represents a battery in electrical diagrams?

• AC symbol

• Ground connection

• DC symbol for rectified current

• DC symbol for battery

What does the 'W' in the power triangle represent?

• Watts

• Volts

• Amps

• Ohms