A crystal oscillator :
(A) Gives high output voltage
(B) Works at high efficiency
(C) Frequency of oscillation remains constant
(D) Requires very low DC supply
Answer - - C

 In a load flow study if |V|and  |δ| are specified at a bus. This bus is known as :
(A) Slack bus
(B) Load bus
(C) Voltage controlled bus
(D) None of these
Answer - - A

If P, be the iron loss and P, be the full load copper loss in a transformer, the ratio of rated load current to load current at which maximum efficiency occurs is:
(A) (Pi/Pc) ^1/2
(B) (Pc/Pi) ^1/2
(C) Pi/Pc
(D) Pc/Pi

Answer - - A

The power factor under-excited synchronous motor is always
(A) Leading
(B) Lagging
(C) Unity
(D) more than unity

Answer - - B

A source has an emf of 10 V and an impedance of (500+j100) ohms. The amount of maximum power transferred to the load will be
(A) 0.5 mw
(B) 0.05 mw
(C) 0.05 w
(D) 0.5 w

Answer - - C

A DC series motor should not be started
(A) at full load
(B) at no load
(C) with half of the full load
(D) none of the above

Answer - - A

The surge impedance of 400 km long overhead transmission line is 400 ohms, For a 200 km length of the same line, the surge impedance :
(A) 200 ohm
(B) 800 ohm
(C) 400 ohm
(D) 100 ohm

Answer - - C

The insulation strength of a EHV transmission  line is mainly governed by :
(A) Load power factor
(B) Harmonies
(C) Corona
(D) Switching over voltage

Answer - - D

 
A cavity is a
(A) Low pass filter
(B) High pass fiter
(C) Band pass filter
(D) None of these
Answer - - C

The power factor of an alternator is determined by its
(A) Speed
(B) Load
(C) Excitation
(D) Prime mover
Answer - - B

An 8 pole wave connected d.c. generator has 900 armature conductors and a flux per pole of0.04 Wb. At what speed if must be driven to generator 500 V?
(A) 208.33 r.p.m
(B) 20.833 r.p.m.
(C) 900 r.p.m.
(D) 1600 r.p.m.
Answer - - A

A. shunt d.c. motor of armature circuit resistance 0.25 is connected to a 230 volt d.c. supply. The input line current is 8 A and the shunt field current 0.8 A. The e.m.f. generated in the armature is
 (A) 230 V
 (B) 228.2 V
(C) 231.8 V
(D) 250 V
Answer - - B

The........current of a junction FET (JFET) is practically zero.
(A) Anode
(B) Gate
(C) Cathode
(D) All of the above

Answer - - B

The difference between the measured value and the true value is called-

(A) Gross error

(B) Relative error 

(C) Probable error

(D) Absolute error 

Answer - - D

Ring main distribution system is more reliable because of-

(A) More protective devices used

(B) Two or more sources of supply 

(C) Higher size of conductor used

(D) Higher load current

Answer - - B

Given (135)base x + (144)base x = (323)base x. What is the value of X ? 

(A) 5

(B) 3

(C) 12

(D) 6

Answer - - D

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

What is the value of flux in the section of yoke, if the pole flux is  Ф weber?

A. Ф x Ф
B. Ф^1/2
C. Ф/2
D. Ф
Answer --C


A 220 V d.c. shunt motor runs at 500 rpm when the armature current is 50 A. If the torque is doubled, the speed will be. (given that Ra= 0.2 )
(A) 500 r.p.m.
(B) 476 r.p.m
(C)576 r.p.m.
(D) 525 r.p.m.
Answer--B

The 'V' curve of synchronous motor shows the relationship between
(A) Applied voltage and back e.m.f.
(B) Back e.m.f. and armature current
 (C) Armature current and rotor field current
 (D) Back e.m.f. and power factor
Answer--C

A certain R-L series combination is connected across a 50 Hz single-phase ac supply. If the instantaneous power drawn was found to be negative for 2 milliseconds in one cycle, the power factor angle of the circuit must be
Options:
 1)90
2) 18
3)36
4)45
 Correct Answer: 36