Quiz: Electrical Engineering
Exam: NPCIL
Topic: Miscellaneous
Each question carries 1 mark.
Negative marking: 1/4 mark
Time: 10 Minute
Q1. Speed of a motor may be varied by varying
a) Field current
b) Applied voltage
c) Resistance in series with armature
d) Any of these
Q2. Which of the following dc motor has approximately constant speed?
a) Series motor
b) Shunt motor
c) Cumulatively compound motor
d) Differentially compound motor
Q3. The diversity factor is defined as the
a) (Average demand)/ (Maximum demand)
b) (Sum of consumers maximum demand)/ (Maximum load on the station)
c) (Maximum demand)/ (Sum of consumers maximum demand)
d) (Average demand)/ (Maximum load on the station)
Q4. The efficiency of the transformer line between
a) 70 to 80%
b) 80 to 90%
c) 90 to 98%
d) none of the above
Q5. The torque produced in a wattmeter is proportional to
a) The average value of current in the two coils
b) The r.m.s. value of currents in the two coils
c) The average value of the supply voltage
d) None of the above
Q6 Which of the following is the best conduct?
a) Copper
b) Aluminum
c) Silver
d) Iron
Q7. In the transformers
a) High tension winding is used near the core
b) High tension winding is used away from the core
c) Low tension winding is used near the core
d) Low tension winding is used away from the core
Q8. Which of the following power system distribution gives the greater reliability?
a) Radial system of the distribution
b) Ring system of the distribution
c) D.C. three wire system of the distribution
d) A.C. three phase four wire system
Q9. A dc motor is preferred to an ac motor for the application in
a) Low speed operation
b) High speed operation
c) Variable speed variation
d) Fixed speed operation
Q10. In a dc motor, maximum power is developed when supply voltage is equal to
a) 1/2 back emf
b) √2 back emf
c) 2 back emf
d) 1/√2 back emf
Solution
S1. Ans.(d)
Sol. Any of these
S2. Ans. (b)
Sol. Shunt motor
S3. Ans. (b)
Sol. (Sum of consumers maximum demand)/ (Maximum load on the station)
S4. Ans. (c)
Sol. 90 to 98%
S5. Ans. (b)
Sol. The r.m.s. value of currents in the two coils
S6. Ans. (c)
Sol. Silver
S7. Ans. (a)
Sol. High tension winding is used near the core.
S8. Ans. (b)
Sol. Ring system of the distribution
S9. Ans. (c)
Sol. Variable speed variation
S10. Ans.(c)
Sol. 2 back emf
