MCQs of Induction Machines (Electrical Machine - II - 3150910)

Electrical Machine - II (3150910) MCQs

MCQs of Induction Machines

Showing 21 to 30 out of 95 Questions

21.

Induction motor is also known as

(a)	Rotating Transformer
(b)	Singly excited motor
(c)	Asynchronous motor
(d)	All of these

22.

The difference between the synchronous speed (Ns) and the actual speed of the rotor (N) is known as the ______

(a)	rotor rmf speed wrt stator
(b)	slip
(c)	slip speed
(d)	The speed at which rotor shaft slip from bearing

23.

The difference between the speed of the revolving field (Ns) and the rotor speed (N), expressed as a percentage of synchronous speed (Ns) is called __________

(a)	slip speed
(b)	rotor rmf speed wrt stator
(c)	slip
(d)	Speed at which rotor shaft slip from bearing

24.

Slip of three-phase induction motor in per unit is defined by

(a)	S = N_s - N
(b)	_{$S = \frac{N_{s} - N}{N_{s}} \times 100$}
(c)	_{$S = \frac{N_{s} - N}{N_{s}}$}
(d)	N = N_s(1-S)

25.

Which of the following is used to find the actual speed of the rotor?

(a)	= 𝑵𝒔−𝑵
(b)	= (𝑵𝒔−𝑵)/𝑵𝒔 × 𝟏𝟎𝟎
(c)	= (𝑵𝒔−𝑵)/𝑵𝒔
(d)	= 𝑵𝒔 (𝟏−𝑺)

26.

The Rotor frequency (𝑓𝑟) at standstill and running condition is ___________ and __________ respectivelly.

(a)	𝒇𝒓=𝒇 and 𝒇𝒓=𝒔𝒇
(b)	𝒇𝒓=𝒔𝒇 and 𝒇𝒓=𝒇
(c)	𝒇𝒓 =𝒇(𝟏−𝑺) and 𝒇𝒓 =𝒇(𝟏−𝑺^2)
(d)	𝒇𝒓=𝒇 and 𝒇𝒓=𝒔^2𝒇

27.

Both the rotor and stator RMF rotate synchronously with respect to

(a)	Stator
(b)	Rotor
(c)	Slip
(d)	None of these

28.

The Rotor reactance/phase at standstill and running condition is ___________ and __________ respectivelly.

(a)	𝐿 and 𝑠𝐿
(b)	2𝜋s𝑓𝐿 and 2𝜋𝑠𝑓𝐿
(c)	2𝜋𝑠𝑓𝐿 and 2𝜋𝑓𝐿
(d)	2𝜋𝑓𝐿 and 2𝜋𝑠𝑓𝐿

29.

What is the first assumption while deriving Developed torque equation?

(a)	lossless system
(b)	No Saturation
(c)	Cu losses = Iron Losses
(d)	All of these

30.

The magnitude of developed torque will depend on

(a)	The magnitude of Stator RMF
(b)	The magnitude of Rotor RMF
(c)	The angle between Stator and Rotor RMF
(d)	All of these

Showing 21 to 30 out of 95 Questions