# Electrical Engineering Questions with Answers 2017

A generating station has a maximum demand of 30 MW, a load factor of 60% and a plant capacity factor of 50%. The reserve capacity of the plant is (a) 5 MW (b) 4 MW (c) 6 MW (d) 10 MW

01. Ans: (c)

02. A 100 km long transmission line is loaded at 110 kV. If the loss of the line is 15 MW and the load is 150 MVA, the resistance of the line is (a) 8.06 ohms per phase (b) 0.806 ohms per phase (c) 0.0806 ohms per phase (d) 80.6 ohms per phase

02. Ans: (a)

When the load on a transmission line is equal to the surge impedance loading (a) The receiving end voltage is less than the sending end voltage (b) The sending end voltage is less than the receiving end voltage (c) The receiving end voltage is more than the sending end voltage (d) The receiving end voltage equal to the sending end voltage

03. Ans: (d)

04. The inductance of single phase two wire power transmission line per km gets doubled when the (a) Distance between wires is doubled (b) Distance between the wires is increased four fold (c) Distance between the wires is increased as square of the original distance (d) Radius of the wire is doubled

04. Ans: (c)

05. The dielectric strength of impregnated papers is about (a) 20 kV/mm (b) 30 kV/mm (c) 15 kV/mm (d) 5 kV/mm

05. Ans: (b)

06. HVDC transmission is preferred to EHV AC because (a) HVDC terminal equipments are inexpective (b) VAR compensation is not required in HVDC systems (c) System stability can be improved (d) Harmonic problem is avoided

06. Ans: (c)

07. Zero-sequence current is used for relaying purpose only in the case of (a) Phase over current relay (b) Phase impedance relay (c) Ground over current relay (d) Ground impedance relay

07. Ans: (d)

08. A 10 kVA, 400 V/200 V single phase transformer with 10% impedance draws a steady short-circuit line current of (a) 250A (b) 50 A (c) 150 A (d) 350 A

08. Ans: (a)

09. In a 3-phase extra-high voltage cable, a metallaic screen around each core insulation is provided to (a) Facilitate heat dissipation (b) Give mechanical strength (c) Obtain longitudinal electric stress (d) Obtain radial electric stress

09. Ans: (b)

10. The severity of line to ground and three phase faults at the terminals of an unloaded synchronous generator is to be same. If the terminal voltage is 1.0 pu, Z1=Z2=j0.1 p.u. and Z0= j0.05 p.u. for the alternator, then the required inductive reactance for neutral grounding is (a) 0.05 p.u. (b) 0.0166 p.u. (c) 0.1 p.u. (d) 0.15 p.u. 10.

Ans: (b)