POWER SYSTEMS QUIZ

The insulation resistance of the 20 km long underground cable is 8 MΩ. Other things being same, the insulation resistance of 10 km long cable will be

8 MΩ

32 MΩ

16 MΩ

4 MΩ

TRUE ANSWER : ?
YOUR ANSWER : ?

The rating of fuse wire is always expressed in

amperes.

ampere-volts.

ampere-hours.

kWh.

TRUE ANSWER : ?
YOUR ANSWER : ?

If the frequency is increased, then skin effect will

remains unaffected

any of the above

decreases

increases

TRUE ANSWER : ?
YOUR ANSWER : ?

An ACSR conductor has a diameter of 2 cm has internal inductance of 0.05 mH/Km. If this ACSR is replaced with another having a diameter of 4 cm then its internal inductance is

0.05 mH/Km

0.1 mH/Km

0.025 mH/Km

0 mH/Km

TRUE ANSWER : ?
YOUR ANSWER : ?

The value of diversity factor is

greater than 1

less than 1

1

0

TRUE ANSWER : ?
YOUR ANSWER : ?

A guard ring is used in string type insulator having 3 units to improve string efficiency. Find the capacitance of metal link 2 if pin to earth capacitance of each unit is 1 F?

4 F

1 F

2 F

0.5 F

TRUE ANSWER : ?
YOUR ANSWER : ?

The capacitance of an overhead transmission line increases with

increase in mutual geometrical mean distance

both 1 and 2

increase in height of conductors above ground

neither 1 nor 2

TRUE ANSWER : ?
YOUR ANSWER : ?

A three phase, 33 kV oil circuit breaker is rated 1200 A, 2000 MVA, 3 secs. The symmetrical breaking current is

55 kA.

50 kA.

35 kA.

45 kA.

TRUE ANSWER : ?
YOUR ANSWER : ?

Which of the following is/are the advantages of synchronous phase modifier over the shunt compensation?

single unit can be used as both capacitance and inductor by adjusting the excitation

both 1 and 2

smooth voltage regulation is possible by controlling excitation

initial cost is low

TRUE ANSWER : ?
YOUR ANSWER : ?

To improve the efficiency of thermal power plant ________________ is placed between boiler and turbine.

air preheater.

superheater.

ash handling point.

economizer.

TRUE ANSWER : ?
YOUR ANSWER : ?

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