Which of the following combination of a 3 phase transformer can successfully operate in parallel

(A) Y-Y and Y- Δ
(B) Δ-Y and Δ-Δ
(C) Δ-Y and Δ-Y
(D) None of these

Answer - - C

A resistance of 20 ohm, an inductance of 0.2H and a capacitance of 100 uF are connected in series across a 220 V, 50 Hz supply. The impedance of the circuit  is
(A) 71ohm
(B)  11ohm
(C) 3.690ohm
(D) 36.9ohm

Answer - - D
A 50 MVA, 1I KV, 39 alternator supplies full load at a lagging power factor of 0.7. What would be the percentage increase in earning capacity if the load power is increased to 0.95?

(A) 3. 57%
(B) 2.63%
(C) 26.3%
(D) 35.7%

Answer - - D
The maximum demand on a power station is 100 MW. If the annual load factor is 40%, the total energy generated in a year will be

(A) 3504 × 10^4 KWH
(B) 3504 × 10^5 KWH
(C) 3.504 × 10^4 KWH
(D) 3.504 × 10^5 KWH

Answer - - B

For successful working of ground wire, the footing resistance of tower should be
( A) Low
(B) High
(C) Medium
(D) None of these 

Answer - - A
A single phase line has two parallel conductors 2 meters apart. The diameter of each conductor is 1.2 cm, the loop inductance per km of the line will be
(A) 2.423 mH
(B) 24.23 mH
(C) 242.3 mH
(D) None of these 

Answer - - A