Top 150+ Solved DC Generators MCQ Questions Answer
Q. If residual magnetism is present in a D.C. generator, the induced e.m.f. at zero speedwill be
a. zero
b. small
c. the same as rated voltage
d. high
Q. Which of the following generating machine will offer constant voltage on allloads ?
a. Self-excited generator
b. Separately excited generator
c. Level compounded generator .
d. All of the above
Q. Which of the following generators will be preferred if they are required to berun in parallel ?
a. Shunt generators
b. Series generators
c. Compound generators
d. None of the above
Q. Two generators are running in parallel. One of the generators may run asmotor for which of the following reasons ?
a. The direction of that generator is reversed
b. The speed of that generator is increased
c. The field of that generator is weakened
d. That generator takes large share of loads
Q. A series generator can self-excite
a. only if the load current is zero
b. only if the load current is not zero
c. irrespective of the value of load current
d. none of the above
Q. A D.C. generator works on the principle of
a. Lenz's law
b. Ohm's law
c. Faraday's law of electromagnetic induction
d. none of the above
Q. A shunt generator can self-excite
a. only if the resistance of the field circuit is less than critical value
b. only if the resistance of the field circuit is greater than critical value
c. irrespective of the value of the resis-tance in the field circuit
d. none
Q. The terminal voltage of a series generator is 150 V when the load current is 5 A. If the load current is increased to 10 A, the terminal voltage will be
a. 150 V
b. less than 150 V
c. greater than 150 V
d. none of the above
Q. The open circuit voltage of a compound generator is 250 V. At full load the terminal voltage
a. will be less than 250 V
b. will always be 250 V
c. may be greater or less than 250 V
d. none of the above
Q. The essential condition for parallel operation of two D.C. generators is thatthey have '
a. same kW rating
b. the same operation r.p.m.
c. the same drooping voltage charac-teristics
d. same percentage regulation
Q. When two D.C. generators are running in parallel an equilizer bar is used
a. to increase the series flux
b. to increase the generated e.m.f.
c. to reduce the combined effect of ar-mature reaction of both the machines
d. so that the two identical machines will pass approximately equal currents to the load
Q. With a D.C. generator which of the following regulation is preferred ?
a. 100% regulation
b. infinite regulation
c. 50% regulation
d. 1% regulation
Q. Which generator would you prefer for feeding long D.C. transmission lines ?
a. Series generator
b. Shunt generator
c. Over compound generator
d. Flat compound generator
Q. In a D.C. generator the critical resistance can be increased by
a. increasing its field resistance
b. decreasing its field resistance
c. increasing its speed
d. decreasing its speed