Power system MCQ #2

Power system MCQ 21 to 25:

21) The rated voltage of a 3 phase power system is given by ____________.
              A) rms peak voltage
              B) Peak phase voltage
              C) rms line to line voltage
              D) Peak line to line voltage

22)  In transmission system, the weight of copper used is proportional to
              A) Square of voltage
              B) Voltage
              C) 1 / (square of voltage)
              D) 1 / voltage

23) Line efficiency increases for ________ transmission voltages.
              A) Higher
              B) Lower
              C) Both (a) and (b)
              D) None of these

24) What is the main drawback of overhead system over underground system?
              A) Surge problem
              B) High initial cost
              C) Higher charging current
              D) Underground system is more flexible than overhead system

25)  What is the highest possible transmission voltage in India?
              A) 675 kV
              B) 765 kV
              C) 132 kV
              D) 440 kV

ANSWER: | 21-C | 22-C | 23-A | 24-A | 25-B |


Power system MCQ 26 to 30:

26) What is the main reason for using the high voltage for the long distance power transmission?
              A) Reduction in the transmission losses
              B) Reduction in the time of transmission
              C) Increase in system reliability
              D) None of these

27) By increasing the transmission voltage double of its original value, the same power can be dispatched keeping the line losses _______________.
              A) Equal to its original value.
              B) Half of its original value.
              C) Double the original value.
              D) One - fourth of the original value.

28) Which among these is not the component of overhead transmission lines?
              A) Conductors
              B) Cross arms
              C) Insulator plates
              D) Transformers

29) The most ideal material for the over head conductor is copper. What are the advantages of this?
              A) Smaller cross sectional area.
              B) Area offered by the wind loads is reduced.
              C) The price of copper is less.
              D) Both (a) and (b).

30) Why is A.C.S.R conductor used as the replacement or substitute for copper?
              A) Higher current carrying capacity.
              B) Economy.
              C) Being less weight.
              D) Higher tensile strength.

ANSWER: | 26-A | 27-D | 28-D | 29-D | 30-B |


Power system MCQ 31 to 35:

31) In India, which types of poles are commonly used for distribution?
              A) Wooden poles
              B) RCC poles
              C) Steel poles
              D) Both (b) and (c)

32) What is the main purpose for guy wire?
              A) Supports the pole
              B) Protects against the surges
              C) Provides emergency earth route
              D) All of these

33) Safety factor is the ratio of
              A) Working stress to breaking stress.
              B) Breaking stress to working stress.
              C) 1 / breaking stress.
              D) 1 / working stress.

34) What is the minimum clearance provided for the 132 kV line from the ground?
              A) 3.2 m.
              B) 6.4 m.
              C) 7.5 m.
              D) 10.5 m.

35) What is the horizontal spacing between phase conductors of 132 kV line?
              A) 8 m.
              B) 11 m.
              C) 14 m.
              D) 17 m.

ANSWER: | 31-D | 32-A | 33-B | 34-B | 35-A |


Power system MCQ 36 to 40:

36) Which type of insulator is used on 132 kV transmission lines?
              A) Pin type
              B) Disc type
              C) Shackle type
              D) Pin and shackle type

37) What is the maximum voltage level upto which the pin type insulators can be used? 
              A) 22 kV
              B) 33 kV
              C) 66 kV
              D) 132 kV

38) Why are the boosters inserted in the circuit?
              A) Reduce current
              B) Increase current
              C) Reduce voltage drop
              D) Compensate for voltage drop

39) Where are the strain type of insulators used?
              A) Low voltage overhead lines
              B) Dead ends
              C) Change in direction of the transmission lines
              D) Both (b) and (c)

40) The maximum voltage of the disc type insulators is at
              A) Same at all points
              B) Near the tower or starting of the insulator
              C) Near to the conductors
              D) None of these

ANSWER: | 36-B | 37-B | 38-D | 39-D | 40-C |