Transmission and Distribution MCQs | Transmission and Distribution Short Questions and Answers

Questions
41 The topmost wire in a distribution line is
A Phase wire
B Earth wire
C Neutral wire
D Any of these

Answer: Earth wire
42 The string efficiency of an insulator can be increased by
A Reducing the number of strings in the insulator
B Increasing the number of strings in the insulator
C Correct grading of insulators of various capacities
D None of these

Answer: Correct grading of insulators of various capacities
43 Due to skin effect at high frequencies, the effective value of conductor resistance
A Increases
B Decreases
C Remains unaltered
D May increases or decrease

Answer: Increases
44 Conductors used in high voltage transmission lines are stranded to
A Increases its tensile strength
B Increase its conductivity
C Reduce the cost
D Make it easy to handle

Answer: Increases its tensile strength
45 Relative to fair weather, in humid weather corona occurs at
A Almost the same voltage
B Higher voltage
C Lower voltage
D None of these

Answer: Lower voltage
46 Transmission lines are classified as short, medium and long depending on the
A Length of line
B Charging current or on load current
C Capacitance of line
D Both (a) and (b) above

Answer: Both (a) and (b) above
47 Reactive power can be injected into a transmission line by using
A Series capacitors
B Shunt capacitors and reactors
C Synchronous capacitors
D Any of these

Answer: Any of these
48 As the height of a transmission tower is altered, the parameter which changes is
A Conductance
B Capacitance
C Inductance
D None of these

Answer: Capacitance
49 In conductor of power transmission line, the voltage gradient is maximum at its
A Surface
B Circle with half the radius
C Centre
D Somewhere between (b) and (c) above

Answer: Surface
50 EHV cable are filled with thin oil under pressure to
A Prevent formation of voids
B Prevent entry of moisture
C To strengthen the cable conductor
D To provide insulation

Answer: Prevent formation of voids
51 cables in power transmission line are provided with intersheaths to
A Minimize charging current
B Provide uniform stress distribution
C Minimize high voltage
D All of these

Answer: Provide uniform stress distribution
52 Temperature increase produces which of the following effect on a transmission line?
A Tension of the conductor and its sag decreases
B Tension of the conductor and its sag increases
C Tension of the conductor decreases and its sag increases
D Tension of the conductor increases and its sag decreases

Answer: Tension of the conductor decreases and its sag increases
53 Impedance and capacitance of a transmission line depend upon
A Current in the line alone
B Voltage in the line alone
C Both (a) and (b)
D Physical configuration of conductors in space

Answer: Physical configuration of conductors in space
54 High tension cable can be used for power transmission for voltages not exceeding
A 11 kV
B 22 kV
C 33 kV
D 110 kV

Answer: 33 kV
55 In short overhead transmission line (upto 80 km), we may neglect
A Series resistance
B Shunt conductance
C Shunt capacitance
D Both shunt conductance and capacitance

Answer: Both shunt conductance and capacitance
56 As the moisture content in the air increases, the disruptive critical voltage
A Remain constant
B Decreases
C Increases
D May increases or decreases

Answer: Decreases
57 If the voltage as well as reactance of a transmission line is double, the maximum steady state power limit of the line
A Remains unaltered
B Doubles
C Becomes 4 times
D Becomes 8 times

Answer: Doubles
58 Rise of temperature of transmission line
A Increases the stress and decreases the length
B Increases the stress and increases the length
C Decreases the stress and increases the length
D Decreases the stress and decreases the length

Answer: Decreases the stress and increases the length
59 A short transmission line has equivalent circuit consisting of
A Series resistance R and series inductance L
B Series resistance R and series capacitance C
C Series resistance R and series capacitance G
D Series inductance L and series capacitance G

Answer: Series resistance R and series inductance L
60 Proximity effect is due to current flowing in the
A Earth
B Sheath
C Neighbouring conductor
D All of these

Answer: Neighbouring conductor
junior administrative assistant jaa test series