Design of AC Machines (2170909) MCQs

MCQs of Design of Three Phase Induction Motor

Showing 71 to 80 out of 97 Questions
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71.

In the design of a wound rotor three-phase induction motor. To avoid excessive rotor copper loss, 

(a)

𝜹𝒓 < 𝜹𝒔
(b)

𝜹𝒓 <<< 𝜹𝒔
(c)

𝜹𝒓 ≅ 𝜹𝒔
(d)

All of these
Answer:

Option (c)

72.

In the design of a small rating wound rotor three-phase induction motor.  ________________ is used.

(a)

Circular conductors – Mesh Winding
(b)

rectangular conductors – Double-layer bar type wave winding
(c)

Circular conductors – Double-layer bar type wave winding
(d)

rectangular conductors  – Mesh Winding
Answer:

Option (a)

73.

In the design of a large rating wound rotor three-phase induction motor.  ________________ is used.

(a)

Circular conductors – Mesh Winding
(b)

rectangular conductors – Double-layer bar type wave winding
(c)

Circular conductors – Double-layer bar type wave winding
(d)

rectangular conductors  – Mesh Winding
Answer:

Option (b)

74.

in general, what is the width to thickness ratio of rectangular conductors used in wound rotor winding?

(a)

2 - 4
(b)

3 - 4
(c)

16 - 9
(d)

2.5 - 4
Answer:

Option (d)

75.

What is the Important of Circle Diagram in three-phase induction motor?

(a)

Performance of the induction motor at various load condition can be easily found by performing No Load Test once.
(b)

Performance of the induction motor at various load conditions can be easily found with one circle diagram.
(c)

Both
(d)

none of these
Answer:

Option (c)

76.

Why locus of the current did not start from the origin (where X and Y-axis start) in the case of circle diagram of a three-phase induction motor?

(a)

due to stator and rotor copper loss
(b)

because its rotating device
(c)

even at no load. IM draw the No-Load Current (Io) due to Mechanical Losses And Iron Losses
(d)

All of these
Answer:

Option (c)

77.

In the equation of current, 𝑰 = (𝑽/𝑿)×𝒔𝒊𝒏⁡∅.   𝒔𝒊𝒏⁡∅ = ___________ 

(a)

diameter of the circle
(b)

power factor angle
(c)

Both diameter of the circle & power factor angle
(d)

None of these
Answer:

Option (b)

78.

In the equation of current, 𝑰 = (𝑽/𝑿)×𝒔𝒊𝒏⁡∅.   𝑽/𝑿 = ___________ 

(a)

power factor angle
(b)

diameter of the circle
(c)

Both diameter of the circle & power factor angle
(d)

None of these
Answer:

Option (b)

79.

The power factor of the three-phase induction motor depends upon

(a)

Magnetizing current (Im)
(b)

Ideal short circuit current (Isc)
(c)

length of Air Gap
(d)

All of these 
Answer:

Option (d)

80.

The power factor of the induction motor will decrease with

(a)

With increase in Magnetizing current
(b)

With an increase in the value of leakage reactance
(c)

With a decrease in Ideal short circuit current
(d)

All of these
Answer:

Option (d)

Showing 71 to 80 out of 97 Questions
5 6 7 8 9 10