Lucknow Metro Questions

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Q1:- Buchholz relay is 

1. water actuated
2. gas actuated 
3. voltage actuated
4. current actuated

ANSWER:- 2

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Q2:- Differential relay protects  the device for following type of fault 

1. internal faults only 
2. depends on the setting of relays 
3. both internal and external faults 
4. external faults only 

ANSWER:-4

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Q3:- Choose the correct statement about ckt breakers

1. the making capability of circuit breaker should be root 2   times than breaking capability 
2. the making capability of circuit breaker should be 2.55   times than breaking capability 
3. the making capability of circuit breaker should be equal to breaking capability
4. the breaking capability of circuit breaker should be 2.55   times than making capability

ANSWER:-2

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Q4:- The function of economiser in thermal power plant is to 

1. extract heat from flue gases and uses it heating feed water to boiler
2. condense the steam exhasusted from turbine
3. remove carbon particles from flue gases.
4. increase temp of steam coming from boiler admitting to turbine

ANSWER:-1

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Q5:- In differential relay percentage bias is defined the ratio of 

1. difference of current in operating coil to the mean circulating current in restraning coil
2. mean current is restraining coils to the difference of current in operating coil
3. difference of current in restraining coils to the mean current in operating coil 
4. mean current in operating coil to the difference of current in restraning coils

ANSWER:-1

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