AP ECET EEE 2016-9

1.A series generator is running at its normal speed and output is open circuited. The terminal voltage developed is

A. Rated voltage
B. Zero voltage
C. Small voltage
D. Double the rated voltage

Answer : Small voltage
Explain:-

2.The field resistance of a dc shunt generator is 200 ohms, this resistance line drawn on the open circuit characteristics cut the o.c. curve at a point (400V, 2.0A). The emf developed is

A. 200V
B. 400V
C. 800V
D. 410V

Answer : 400V
Explain:-

3.The essential condition for satisfactory parallel operation of two generators is that they should have the same

A. kW output rating
B. Drooping voltage characteristics
C. Percentage regulation
D. Speed of operation

Answer : Drooping voltage characteristics
Explain:-

4. The current drawn by a 120V dc shunt motor of armature resistance of 0.5 ohm and back emf 110V is

A. 20 A
B. 24 A
C. 22 A
D. 5 A

Answer : 20 A
Explain:-

5. The maximum torque of dc motors is limited by

A. Commutation
B. Heating
C. Speed
D. Armature current

Answer : Commutation
Explain:-

6.The main disadvantage of 3- point starter is

A. Unsuitable for large currents
B. Unsuitable for variable speed motors
C. Cannot be used for overload currents
D. Can be used to start dc generators

Answer : Unsuitable for variable speed motors
Explain:-

7.Performance of large dc machines regarding commutation and temperature rise at full load can be checked by ______ test

A. Brake
B. Swinburne's
C. Hopkinson's
D. Retardation

Answer : Hopkinson's
Explain:-

8. Air friction damping is used in ______ type of instrument

A. Moving iron
B. Moving coil
C. Induction
D. Hot wire

Answer : Moving iron
Explain:-

9. The burden of current transformer is expressed in

A. Volt-amp rating
B. Current rating of secondary winding
C. Voltage rating of secondary
D. Watt reading

Answer : Volt-amp rating
Explain:-

10.Loss of charge method is used for measurement of

A. Low R
B. Low L
C. High R
D. High L

Answer : High R
Explain:-