1. When a DC motor is connected across AC supply, it will
(a) fail to start.
(b) run at normal speed.
(c) burn.
(d) run at lower speed. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] D [/accordion-item][/accordion]
2. Which DC motor is most suitable for high starting torque applications?
(a) shunt.
(b) series.
(c) cumulative compound.
(d) differential compound. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] B [/accordion-item][/accordion]
3. Which of the following DC Motor has negative speed regulation?
(a) Shunt motor.
(b) Series motor.
(c) Differential compound motor.
(d) Community compound motor. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] C [/accordion-item][/accordion]
4. Which of the following DC motor has poorest speed regulation?
(a) cumulative compound.
(b) differential compound.
(c) series.
(d) shunt. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] C [/accordion-item][/accordion]
5. If the load on a DC shunt motor is increases, its speed is slightly reduced due to
(a) increase in armature current.
(b) increase in flux.
(c) decrease in reactance.
(d) decrease in back emf. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] D [/accordion-item][/accordion]
6. In which of the following device the generated emf and armature current are in the opposite directions?
(a) dc generator.
(b) dc motor.
(c) transformer.
(d) all of the above. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] B [/accordion-item][/accordion]
7. With the increase in temperature, the speed of DC shunt motor
(a) decreases.
(b) increases.
(c) remain same.
(d) none of the above. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] B [/accordion-item][/accordion]
8. With the increase in temperature, the speed of DC series motor
(a) decreases.
(b) increases.
(c) remain same.
(d) none of the above. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] A [/accordion-item][/accordion]
9. If the field winding resistance of a DC shunt motor is increases, its speed will
(a) decreases.
(b) increases.
(c) remains same.
(d) none of the above. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] B [/accordion-item][/accordion]
10. Which of the following method is used for the speed control of DC shunt motor?
(a) voltage control method.
(b) flux control method.
(c) rheostat control method.
(d) all of the above. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] D [/accordion-item][/accordion]
11. A dc series motor should not be started on no load because it would
(a) not develop starting torque.
(b) fail to start without load.
(c) run at dangerously high speed.
(d) draw more current without producing sufficient torque. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] C [/accordion-item][/accordion]
12. In a DC motor the inter-pole winding is connected in
(a) series with field winding.
(b) series speed armature winding.
(c) parallel big field winding.
(d) parallel with armature winding. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] B [/accordion-item][/accordion]
13. Armature reaction in dc motor results
(a) decrease in speed.
(b) increase in speed.
(c) short circuit.
(d) open circuit. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] B [/accordion-item][/accordion]
14. Which of the following test can be performed on DC series motor?
(a) Swinburne test.
(b) Hopkinson test.
(c) Brake test.
(d) Field test. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] D [/accordion-item][/accordion]
15. While performing Swinburne test, the iron losses are assumed to be
(a) negligible.
(b) constant.
(c) zero.
(d) variable. [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] B [/accordion-item][/accordion]