Design of AC Machines (2170909) MCQs

MCQs of Design of Three Phase Induction Motor

Showing 51 to 60 out of 97 Questions
51.

While designing a three-phase induction motor. To keep Iron Losses & Magnetizing MMF within the limit. Flux density in the Rotor Core should not exceed the ______ Wb/m2 

(a)

1.1 to 1.4

(b)

1.1 to 1.7

(c)

1.5

(d)

1.7

Answer:

Option (c)

52.

While designing a three-phase induction motor. What is the permissible limit of core flux density?

(a)

1.5

(b)

1.1 to 1.7

(c)

1 to 1.8

(d)

1.2 to 1.4

Answer:

Option (d)

53.

Flux in the rotor core section ∅𝒄 = 

(a)

∅π’Ž

(b)

0.5 ∅π’Ž

(c)

1.5 ∅π’Ž

(d)

None of these 

Answer:

Option (b)

54.

In the design of a three-phase induction motor. The Inside Diameter of rotor lamination  can be calculated as

(a)

𝑫i = 𝑫r - 𝑫𝒆𝒑𝒕𝒉 𝒐𝒇 𝑺𝒕𝒂𝒕𝒐𝒓 𝑺𝒍𝒐𝒕 - 𝑫𝒆𝒑𝒕𝒉 𝒐𝒇 π‘ͺ𝒐𝒓𝒆

(b)

π‘«π’Š = 𝑫𝒓 − 𝟐(𝑫𝒆𝒑𝒕𝒉 𝒐𝒇 𝑹𝒐𝒕𝒐𝒓 𝑺𝒍𝒐𝒕 + 𝑫𝒆𝒑𝒕𝒉 𝒐𝒇 𝑹𝒐𝒕𝒐𝒓 π‘ͺ𝒐𝒓𝒆)

(c)

π‘«π’Š = 𝑫𝒓 + 𝟐(𝑫𝒆𝒑𝒕𝒉 𝒐𝒇 𝑹𝒐𝒕𝒐𝒓 𝑺𝒍𝒐𝒕+𝑫𝒆𝒑𝒕𝒉 𝒐𝒇 𝑹𝒐𝒕𝒐𝒓 π‘ͺ𝒐𝒓𝒆)

(d)

None of these

Answer:

Option (b)

55.

In the design of a wound rotor three-phase induction motor. Which of the following must be assumed to identify numbers of rotor slot?

(a)

value of rotor slots per pole per phase

(b)

value of stator slots per pole per phase

(c)

value of rotor inner diameter

(d)

value of rotor outer diameter

Answer:

Option (a)

56.

In the design of a wound rotor three-phase induction motor. The value of rotor slots per pole per phase depends on 

(a)

winding type

(b)

rotor core length

(c)

length of air gap

(d)

rotor diameter

Answer:

Option (a)

57.

In the design of a wound rotor three-phase induction motor. The value of rotor slots per pole per phase for fraction slot winding is selected between 

(a)

1 - 5

(b)

2 - 5

(c)

2.5 - 5

(d)

3 or 4

Answer:

Option (c)

58.

In the design of a three-phase induction motor. The number of rotor slots should never be __________ the number of stator slots

(a)

greater than

(b)

lesser than

(c)

equal to

(d)

Any value

Answer:

Option (c)

59.

Normally ___________ slot used in slip ring rotor of three-phase IM.

(a)

Open

(b)

Closed

(c)

Semi-Closed

(d)

any of these

Answer:

Option (c)

60.

In the design of a wound rotor three-phase induction motor. The Slip-ring rotor has _____________ .  

(a)

balanced 3-Φ winding either connected in Y or Δ

(b)

1-Φ winding

(c)

rotor bare with end rings

(d)

Split-Φ winding

Answer:

Option (a)

Showing 51 to 60 out of 97 Questions