SWITCH GEAR QUIZ

Which of the following is used in liquid fuses ?

distilled water

sulphur hexafluoride

transformer oil

carbon tetrachloride

TRUE ANSWER : ?
YOUR ANSWER : ?

Overheating of relay contacts or contact born out is due to

too low contact pressure

foreign matter on the contact surface

all of these

slow making and breaking of load circuit contacts

TRUE ANSWER : ?
YOUR ANSWER : ?

An isolator is designed to open a circuit under

full load

no load

None of these

normal conditions

TRUE ANSWER : ?
YOUR ANSWER : ?

Back up protection is generally used for protection against

short-circuit faults only

None of these

open-circuit faults only

both open and short-circuit faults

TRUE ANSWER : ?
YOUR ANSWER : ?

When the circuit breaker operates under fault conditions, the greatest noise is produced in

sf6 circuit breaker

oil circuit breaker

air-blast circuit breaker

vaccum circuit breaker

TRUE ANSWER : ?
YOUR ANSWER : ?

The relay operating coil is supplied through

fuse

current transformer

None of these

power transformer

TRUE ANSWER : ?
YOUR ANSWER : ?

Directional relay are based on flow of

All of these

power

voltage wave

current

TRUE ANSWER : ?
YOUR ANSWER : ?

A fuse in a motor circuit provides protection against

overload

None of these

short-circuit and overload

open circuit, short-circuit and overload

TRUE ANSWER : ?
YOUR ANSWER : ?

A circuit breaker is rated as 1500 A, 1000 MVA, 33 kv, 3-second , 3- phase oil circuit breaker. The rated normal current is

1500/√3 A

1500 A

750 A

None of these

TRUE ANSWER : ?
YOUR ANSWER : ?

Insulation resistance of high voltage circuit breakers is more than

1 mega ohms

10 mega ohms

100 mega ohms

500 mega ohms

TRUE ANSWER : ?
YOUR ANSWER : ?

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