Electrical Machine - I (3140913) MCQs

MCQs of DC Machines

Showing 21 to 30 out of 167 Questions
21.
In a lap winding, the dc machine number of conductors is 100, and number of parallel paths are 10. Find the average pitch
(a) 10
(b) 100
(c) 50
(d) 1
Answer:

Option (a)

22.
Lap winding is preferred for which type of machines?
(a) low current and low voltage
(b) high current and high voltage
(c) high current and low voltage
(d) low current and high voltage
Answer:

Option (c)

23.
Wave winding is preferred for which of the following rating?
(a) low current and low voltage
(b) high current and high voltage
(c) high current and low voltage
(d) low current and high voltage
Answer:

Option (d)

24.
Equalizer rings are used in which of the following?
(a) lap winding
(b) wave winding
(c) both 1 and 2
(d) none of the above
Answer:

Option (a)

25.
In a 2 pole lap winding dc machine, the resistance of one conductor is 2Ω and the total number of conductors is 100. Find the total resistance1
(a) 100
(b) 200
(c) 50
(d) 10
Answer:

Option (c)

26.
Dummy coils are used for
(a) increasing efficiency
(b) reducing armature reaction
(c) mechanical balancing
(d) all of the above
Answer:

Option (c)

27.
A 4 pole lap wound dc generator has 4 brushes if one of the brush is damaged, what will be the change in V, I and P ratings
(a) V, I and P
(b) V/2, I/2, and P/4
(c) V/2, I, and P/2
(d) V, I/2, and P/2
Answer:

Option (d)

28.
For a dc machine shunt resistance and armature resistance values are
(a) high and high
(b) high and low
(c) low and low
(d) low and high
Answer:

Option (b)

29.
Shunt field of DC generators consists of ___________ number of turns and _________ conductors respectively
(a) large and thick
(b) large and thin
(c) less and thick
(d) less and thin
Answer:

Option (b)

30.
Series field consists of __________ number of turns and _________ conductors respectively
(a) large and thick
(b) large and thin
(c) less and thick
(d) less and thin
Answer:

Option (c)

Showing 21 to 30 out of 167 Questions