G063A Quiz No 8

A detailed and visually engaging illustration depicting electrical safety concepts, such as undervoltage protection, surge diverters, and circuit breakers in a modern industrial setting.

Electrical Safety and Protection Quiz

Test your knowledge on electrical safety, motor operations, and protection devices with our comprehensive quiz. Brush up on important concepts in electrical engineering and become more informed about how to protect equipment and ensure safe practices.

Key topics covered include:

Motor voltage characteristics
Undervoltage protection
Surge protection components
Current ratings and circuit protection

13 Questions3 MinutesCreated by WiringWizard734

If the voltage supply to an electric motor is lower than the rated voltage, which of the following are true:

The motor will draw excessive current

The motor speed will increase

The motor may overheat

The motor will slow and cool

Which of the following would protect against undervoltage?

Alternate supply

Undervoltage relay

Circuit breaker

Surge diverter

A fault current limiter is:

Resistive component which limits the maximum circuit current

Reactive component designed to oppose current rise when a fault occurs

Circuit opening device to limit the let through energy when a fault occurs

Parallel capacitor which smooths large current fluctuations

An isolating switch installed to isolate a three-phase machine must interrupt:

All conductors

The neutral conductors

At least two phases of a three-phase supply

All active conductors

Answer the following question with reference to the fuse rupturing characteristic graph attached:

For a 63A HRC service fuseto disconnect the supply in 0.4 seconds, how much current is needed to flow through the fuse?

50 amps

150 amps

350 amps

400 amps

A domestic range is being upgraded from a 7.8kW unit to a 9.6kW unit. The cable is sufficient to carry the load but the circuit breaker size needs to be increased. What is an appropriate size breaker for this load?

16A

20A

25A (I=P/V) for three-phase

32A (I=P/V) for single-phase

What does "30mA" marked on a RCD/MCB represent?

Residual tripping current

Overload current

Nominal current

Fault current

What does "6kA" marked on a RCD/MCB represent?

Residual tripping current

Overload current

Nominal current

Fault current

What does "C10" marked on a RCD/MCB represent?

Type C 10A nominal current

Type C 10A fault current

Circuit breaker 10A

Current rating 10A

An over voltage transient in an electrical installation can be caused by:

Switching operations

High bay lights

High power factor loads

A low power factor

Select from the following. List two (2) causes of undervoltage:

Fault in supply system

Voltage drop due to overload

Being too close to the supply transformer

Lightning strike