1. The number of parallel path in a simplex lap winding is equal to
(a) number of poles
(b) number of pole pairs
(c) two
(d) two times number of pole [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] A [/accordion-item][/accordion]
2. The number of parallel path in a simplex wave windings are equal to
(a) two
(b) number of poles
(c) number of poles pairs
(d) no of coils [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] A [/accordion-item][/accordion]
3. The number of parallel path in a 8-pole duplex wave winding is equal to
(a) 2
(b) 4
(c) 8
(d) 16 [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] B [/accordion-item][/accordion]
4. The number of parallel path in a 8-pole duplex lap winding is equal to
(a) 4
(b) 8
(c) 16
(d) 32 [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] C [/accordion-item][/accordion]
5. In DC machine, the fractional pitch winding is used to
(a) produce vibration
(b) reduce sparking
(c) avoid hunting
(d) avoid magnetic locking [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] B [/accordion-item][/accordion]
6. In a DC machine, the sparking at the brushes is due to
(a) low contact resistance
(b) reactance voltage
(c) armature reaction
(d) over excitation [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] B [/accordion-item][/accordion]
7. When the field excitation of a DC generator increases, its generated emf
(a) decreases
(b) increases
(c) remain same
(d) first increases then constant [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] D [/accordion-item][/accordion]
8. The field coil of a DC machine are usually made of
(a) copper
(b) aluminium
(c) carbon
(d) mica [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] A [/accordion-item][/accordion]
9. Then insulating material used between commutator segment is generally
(a) paper
(b) mica
(c) plastic
(d) fibre [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] B [/accordion-item][/accordion]
10. The function of dummy coils in DC machines is to
(a) reduce armature reaction
(b) provide alternate flux
(c) reduce losses
(d) provide mechanical balancing [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] B [/accordion-item][/accordion]
11. Permeability is reciprocal of
(a) susceptibility
(b) reluctivity
(c) permittivity
(d) conductivity[accordion clicktoclose=true tag=h4][accordion-item title=”Answer“] B [/accordion-item][/accordion]
12. The purpose of using dummy coil in a DC machine is to
(a) reduce losses
(b) reduce armature reaction
(c) provide mechanical balance to armature
(d) improve power factor [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] C [/accordion-item][/accordion]
13. The rotor part of a DC machine carries
(a) armature winding
(b) field winding
(c) either field or armature winding
(d) none of the above [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] A [/accordion-item][/accordion]
14. If a field winding designed for series connection is connected in parallel, the machine will
(a) draw very high current
(b) stand still
(c) run normally
(d) run at slow speed [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] A [/accordion-item][/accordion]
15. In the commutative compound machine, the mmf of the series field winding will ________ to the mmf of the shunt field winding.
(a) add
(b) minus
(c) same
(d) half [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] A [/accordion-item][/accordion]
16. Which is the basic dominant factor in the production of the magnetic flux in a compound machine?
(a) Shunt field mmf
(b) Series field mmf
(c) Both shunt and series field mmf
(d) None of the above [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] A [/accordion-item][/accordion]
17. The principle of dynamically induced emf is used in
(a) generator
(b) battery
(c) transformer
(d) all of the above [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] A [/accordion-item][/accordion]
18. A dummy coil may required in a DC machine, if the machine is
(a) lap wound
(b) wave wound
(c) either lap or wave wound
(d) none of the above [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] B [/accordion-item][/accordion]
19. In a DC Machine, the frog leg wound armature are designed for the use with
(a) high current high voltage
(b) high current low voltage
(c) moderate current and moderate voltage
(d) low current and low voltage [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] C [/accordion-item][/accordion]
20. Which of the following is main factor to determine the size and rating of and electric machine?
(a) Current
(b) Temperature
(c) Speed
(d) Voltage [accordion clicktoclose=true tag=h4][accordion-item title=”Answer” state=closed] B [/accordion-item][/accordion]
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