DC Generator Multiple Choice Questions and Answers

101. Equilizer rings are required in case armature is

1. wave wound
2. lap wound
3. delta wound
4. duplex wound

102. Copper brushes in D.C. machine are used

1. where low voltage and high currents are involved
2. where high voltage and small cur-rents are involved
3. in both of the above cases
4. in none of the above cases

103. The open circuit voltage of a compound generator is 250 V. At full load the terminalvoltage

1. will be less than 250 V
2. will always be 250 V
3. may be greater or less than 250 V
4. none of the above

104. A sinusoidal voltage of 5 Hz is applied to the field of a shunt generator. The armaturevoltage wave

1. will be zero
2. will be of 5 Hz
3. willbeof5xiVHz
4. will be of v Hz 5

105. A 220 V D.C. generator is run at full speed without any excitation. The open circuitvoltage will be

1. zero
2. about 2 V
3. about 50 V
4. 220 V

106. The e.m.f. induced in the armature of a shunt generator is 600 V. The armatureresistance is 0.1 ohm. If the armature current is 200 A, the terminal voltage will be

1. 640 V
2. 620 V
3. 600 V
4. 580 V

107. If residual magnetism is present in a D.C. generator, the induced e.m.f. at zero speed willbe

1. zero
2. small
3. the same as rated voltage
4. high