Electricity Supply System Quiz

What are the two power companies in Hong Kong?

• The Hongkong Electric Company, Limited (HEC)

• CLP Power Hong Kong Limited (CLP)

• Both A and B

• None of the above

What is the voltage range for low voltage (LV)?

• Not greater than 50V

• Exceeding ELV but not greater than 1000V ac

• Greater than LV

• None of the above

What is the unit of electrical resistance?

• Volt

• Ampere

• Ohm

• Watt

What is the typical supply voltage for a single-phase system in Hong Kong?

• 110V

• 220V

• 380V

• 440V

What are the two types of final distribution circuits?

• Final ring circuit

• Final radial circuit

• Both A and B

• None of the above

What is a fuse?

• A protective device that melts to cut off supply

• A type of circuit breaker

• A type of electrical cable

• None of the above

What is the advantage of a miniature circuit breaker (MCB)?

• Can be reused

• More expensive than a fuse

• Slower tripping time

• None of the above

What are the main objectives of earthing?

What is the working principle of a RCCB?

What is the minimum illumination provided at floor level by the emergency lighting system for a staircase?

• 2 lux

• 1 lux

• 0.5 lux