# MCQ in Power Transmission and Distribution Part 1 | REE Board Exam

(Last Updated On: October 4, 2020) This is the Multiple Choice Questions Part 1 of the Series in Electric Power Transmission and Distribution System Engineering as one of the Electrical Engineering topic. In Preparation for the REE Board Exam make sure to expose yourself and familiarize in each and every questions compiled here taken from various sources including but not limited to past Board Exam Questions in Electrical Engineering field, Electrical Engineering Books, Journals and other Electrical Engineering References.

#### Start Practice Exam Test Questions Part 1 of the Series

Choose the letter of the best answer in each questions.

1. Ferroresonance is an abnormal conditions that occurs at the

a. capacitor

b. Distribution line

c. Transformer

d. Motor

Solution:

2. If a fixed amount of power is to be transmitted over a certain length with fixed power loss, it can be said

a. the volume of conductor required is inversely proportional to the square of voltage and that of the power factor of load

b. the volume of the conductor is inversely proportional to voltage and that of power factor of load

c. the volume of the conductor is proportional to square of the voltage and directly proportional to power factor of load

d. the volume of the conductor required is proportional to voltage only

Solution:

3. Assuming the constant efficiency transmission, if the voltage is increased n times, the size of the conductor would be

a. reduced to 1/n2 that of the original

b. increased to n2 that of the original

c. reduced to 1/n that of the original

d. increased to n times that of the original

Solution:

4. In a distribution system, if the synchronous capacitors are to be used for improving the power factor, the correct location would be

a. at the sending end

b. at the receiving end

c. in middle of the transmission line

d. none of these

Solution:

5. The approximate surge impedance of a transmission line is

a. L/C

b. LC

c. √(L/C)

d. √(LC)

Solution:

6. The transmission of power by overhead lines is much costlier than the underground transmission.

a. true

b. false

c. it depends

d. always

Solution:

7. Shunt conductance in power transmission is due to

a. leakage over the insulators

b. leakage over the conductors

c. leakage over the poles

d. leakage between ground and conductors

Solution:

8. The string efficiency of the insulator can be increased by

a. increasing the number of strings in the insulator

b. increasing ratio, capacity to earth, capacity per insulator

c. correct grading of the various capacitances

d. reducing the number of strings

Solution:

9. Corona helps in avoiding the effect of lightning or surges the transmission line

a. true

b. false

c. on HVDC only

d. on EHV only

Solution:

10. The voltage stress is maximum in the cable

a. at the surface of the sheath

b. at the surface of the conductor

c. at the surface of the insulator

d. at the surface of the armouring

Solution:

11. The graded cables use the dielectrics of different

a. permitivities

b. permeabilities

c. a and b both

d. a or b

Solution:

12. The dielectric losses increase with the increase of ______

a. temperature

b. pressure

c. humidity

d. moist

Solution:

13. If A, B, C and D are the constants of the medium transmission line, which of the following relation is correct?

a. AB – CD = -1

b. AD + BD = 1

c. BC – AD = -1

d. AC – BD = 1

Solution:

14. What is the unit of constant D?

a. ohm

b. mho

c. henry

d. none of these

Solution:

15. While finding out the capacitance is neglected in

a. a short transmission line

b. a long transmission line

c. a medium transmission line

d. all these cases

Solution:

16. The capacitance in the medium transmission line is

a. lumped

b. distributed over the entire length of line

c. a or b depending on the transmission voltage

d. variable non-linearly over line

Solution:

17. The surge impedance of the underground cable is ______ than the surge impedance of the overhead transmission line.

a. less

b. more

c. equal

d. no relation

Solution:

18. The surge impedance of the long transmission line is given by

a. Zc = √(L/C)

b. Zc = √(Z/Y)

c. Zc = √(Y/Z)

d. Zc = √(R/Y)

Solution:

19. Ferranti Effect states that under certain conditions the sending end voltage is

a. less than receiving end voltage

b. greater than receiving end voltage

c. equal to receiving end voltage

d. abnormally high

Solution:

20. If the receiving end voltage is assumed same as the sending end voltage, and the impedance of the line is the resistance of the line. What will be the maximum steady state power transmitted over the line?

a. Vr2/Z

b. Vs2

c. zero

d. very high

Solution:

21. If Vs = VR = 33 kV for three phase transmission and reactance is 13 ohms per phase. What will be the maximum power transmission per phase?

a. 29 MW

b. 28 MW

c. 30 MW

d. 60 MW

Solution:

22. The size of the feeder is determined primarily by

a. the current it is required to carry

b. the percentage variation of voltage in the feeder

c. the voltage across the feeder

d. the distance over which the transmission is made

Solution:

23. If the voltage is increased n times, the current in the feeder is reduced to (for a given power delivered)

a. 1/n times of the original

b. 1/n2 times of the original

c. 1/ n times of the original

d. n times of the original

Solution:

24. In the d.c. three wire transmission system the cross-section of the neutral is generally

a. ¼ of the outer conductors

b. ½ of the outer conductors

c. ⅓ of the outer conductors

d. equal to the outer conductors

Solution:

25. As the transmission voltage increases the percentage resistance drop

a. increases

b. decreases

c. will not change

d. will increase in random manner

Solution:

26. As the transmission voltage increases the volume of the conductor

a. increases

b. decreases

c. will not change

d. will increase proportionately

Solution:

27. The power transmission capacity of the transmission line is

a. proportional to the square of the operating voltage

b. inversely proportional to the voltage

c. proportional to the voltage

d. inversely proportional to the square of the voltage

Solution:

28. The Corona loss in the transmission line can be reduced by

a. increasing spacing between the conductors or the diameter of the conductors.

b. decreasing spacing between the conductors or the diameter of the conductors.

c. decreasing spacing between the conductors and decreasing the diameter of the conductors

d. using double circuit line

Solution:

29. The bundle conductors are preferred for EHV transmission line because

a. it is easy to fabricate thin conductors and combine them to make a bundle

b. overall inductance of the line is reduced and corona loss and radio influences are minimum

c. height of the tower is reduced and hence cheap transmission

d. fabrication of the bundle conductors is cheap

Solution:

30. The effect of shock in the human body will depend on

a. line voltage

b. line current

c. current flowing in the body

d. none of these

Solution:

31. The requirement of the insulation in the transmission line design is determined by

a. current

b. voltage

c. rate of change of the current

d. rate of change of voltage

Solution:

32. It is the Space between the magnetic field and electric field

a. flux

b. Power

c. Insulator

d. permitivity

Solution:

33. Which of the following power system distribution gives the greater reliability?

a. radial system of the distribution

b. ring system of the distribution

c. D.C. three wire system of the distribution

d. A.C. three phase four wire system

Solution:

34. The inductive interference between power and communication line can be minimized by

a. increasing the distance between the conductors

b. transposition of the power line

c. transposition of the communication line

d. using aluminum

Solution:

35. For a 11 kV underground system, it is possible to work upon a length of

a. 800 miles

b. 100 miles

c. 400 miles

d. none of these

Solution:

36. Series capacitors are used to

a. improve line voltage

b. compensate line inductive reactance

c. compensate line capacitive reactance

d. none of these

Solution:

37. Advantage of power system interconnection is

a. Large size circuit breakers are required because of large short-circuit currents

b. Machines of one system remain in step with machines of another system

c. Fewer machines are required as reserve for operation at peak loads

d. Optimization of machine can be done properly

Solution:

38. The capacitance and inductance per unit length of a 3-phase line, operating at 110 kV are 0.01 microfarad and 2.5 mH. The surge impedance of the line is

a 50 ohms

b. 750 ohms

c. 250 ohms

d. 500 ohms

Solution:

39. A long transmission line is energized at then sending end and is kept open circuited at the receiving end. The magnitudes of the sending end voltage Vs and of the receiving end voltage Vr satisfy the following relationship

a. Vs =Vr = 0

b. Vs is greater than Vr

c. Vs is less than Vr

d. Vs =Vr

Solution:

40. Voltage regulation of a short transmission line is

a. always positive

b. always negative

c. either positive, negative , or zero

d. always lagging

Solution:

41. Shunt compensation for long EHV lines is primarily resorted to

a. improve voltage profile

b. improve stability

c. reduce fault currents

d. eliminate fault

Solution:

42. Series compensation is primarily resorted to

a. improve voltage profile

b. improve instability

c. reduce fault currents

d. improve stability

Solution:

43. Fair weather corona loss may be computed using the empirical formula given by Peterson. According to Peterson’s formula corona loss is proportional to

a. f and V2

b. f2 and V

c. f and V

d. f only

Solution:

44. Bundled conductors are used in EHV lines primarily for

a. reducing cost of the line

b. reducing corona loss and radio interference

c. increasing stability limit.

d. reduce internal inductance

Solution:

45. In a double-circuit line with hexagonal spacing ,

a. The phases are balanced, but the conductors of each individual phase are not balanced.

b. The conductors of each individual phase are balanced , but the phases are not balanced

c. The phases, and the conductors of each individual phase are both balanced

d. Is better for High voltage

Solution:

46. The Self GMR considering the total effective outside radius method is used to evaluate:

a. Inductance.

b. Capacitance

c. Inductance and Capacitance both.

d. None of these of the overhead transmission lines.

Solution:

47. In EHV transmission lines, efficiency of transmission can be increased by decreasing the corona loss. This is achieved by:

a. Increasing the distance between the line conductors.

b. Using bundled conductors.

c. Using thick conductors.

d. Using thin conductors.

Solution:

48. When two conductors are “bundled”:

a. The potential gradient in space is increased.

b. Corona losses are eliminated.

c. The potential gradient around them is equivalent to that which would exist with one large-diameter conductor.

d. Capacitive reactance remains the same

Solution:

49. Two or three sheds or petticoats are provided in pin-type insulators in order to increase

a. creepage resistance

b. spark-over voltage(S.O.V)

c. puncture voltage

d. increase sag

Solution:

50. Pin -type insulators are use up to

a. 600 V

b. 34.5 kV

c. 115 kV

d. 13.8 kv

Solution:

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