### MCQs of Basic Principles

Showing 41 to 50 out of 135 Questions
41.
Surge impedance of 400 Ω means
 (a) Line can be theoretically loaded upto 400 Ω (b) Line can be practically loaded upto 400 Ω (c) Open circuit impedance of 400 Ω (d) Short circuit impedance of 400 Ω
42.
By increasing the transmission voltage to double of its original value the same power can be dispatched keeping the line loss
 (a) Equal to original value (b) Half the original value (c) Double the original value (d) One fourth of original value
43.
In a short transmission line, voltage regulation is zero when the power factor angle of the load at the receiving end side is equal to
 (a) tan–1 (X/R) (b) tan–1 (R/X) (c) tan–1 (X/Z) (d) tan–1 (R/Z)
44.
A 3-phase, 50 Hz transmission line has a capacitance of line to neutral Cn = 0.01 μF/km. The voltage of the line is 100 kV. The charging current per kilometer of line is
 (a) 181 A/km (b) 181×10–3 A/km (c) 5.51 A/km (d) 1.73×103 A/km
45.
If in a line, resistance and reactance are found to be equal and regulation is zero, then load will be
 (a) Unity power factor (b) Zero power factor (c) 0.707 (lead) power factor (d) 0.707 (lag) power factor
46.
The charging current of 400 kV line is more than that of a 220 kV line of the same length
 (a) True (b) False (c) Insufficient data
47.
A synchronous machine is
 (a) A single excited machine (b) A doubly excited machine (c) Made to run at a speed less than Ns (d) Generally a lagging power factor machine
48.
The per unit value of a 2 Ω resister at 100 MVA base and 10 kV base is
 (a) 4 pu (b) 2 pu (c) 0.5 pu (d) 0.2 pu
49.
The regulation of line at full load, 0.8 lagging power factor is 11%. A long line under no load condition, for a good voltage profile needs
 (a) Shunt resistance at receiving end (b) Shunt reactor at receiving end (c) Shunt capacitor at receiving (d) All of above
50.
For a 500 Hz frequency excitation, a 100 km long power line will be modeled as
 (a) Short line (b) Medium line (c) Long line (d) None of above
Showing 41 to 50 out of 135 Questions