Test: Fractional KW Motors of Electrical Machines- 2

Question 1

A single phase induction motor is

Accepted Answer

self starting with the help of an auxiliary winding

Answer

self starting

Answer

not self starting

Answer

none of the above

Question 2

The capacitor in a capacitor-start induction run ac motor is connected in series with

Accepted Answer

starting winding

Answer

compensating winding

Answer

squirrel cage winding

Answer

running winding

Question 3

Which of the following statements associated with shaded pole induction motor is incorrect?

Accepted Answer

It has high operating efficiency.

Answer

It has squirrel cage type rotor.

Answer

It is one of the simplest and cheapest single phase induction motor.

Answer

It has laminated salient poles each provided with its own exciting coil.

Question 4

Assertion (A) : In a single phase induction motor, while the motor is connected to single phase ac supply and is rotating, the two fields (stator and rotor field) combine to form a resultant rotating field revolving at a synchronous speed.
Reason (R) : The rotor field created by rotor currents acts at right angle to the stator field and also lags the stator field by 90° electrical degrees in time phase.

Accepted Answer

Both A and R are true and R is a correct explanation of A.

Answer

Both A and R are true but R is not a correct explanation of A.

Answer

A is true but R is false.

Answer

A is false but R is true.

Question 5

Assertion (A) : Linear induction motor wide use in industry and electric traction.
Reason (R) : Linear induction motors are cheaper in initial as well as in maintenance costs.

Accepted Answer

Both A and R are true but R is not a correct explanation of A.

Answer

Both A and R are true and R is a correct explanation of A.

Answer

A is true but R is false.

Answer

A is false but R is true.

Question 6

In comparison to a resistance start motor, the capacitor start motor has
1. high starting torque
2. high running torque
3. larger phase difference between two winding currents
4. low starting current
Out of these, the correct answer is

Accepted Answer

1, 3 and 4

Answer

1, 2, 3 and 4

Answer

3 and 4

Answer

1 and 4

Question 7

The direction of rotation of a shaded pole induction motor

Accepted Answer

can’t be reversed unless there is a provision for shifting of shading coil from one half to the other half of the pole.

Answer

can be reversed by interchanging main winding terminals.

Answer

can be reversed by interchanging the supply terminals.

Answer

can be reversed by open-circuiting the shading rings.

Question 8

In various types of split-phase, 1-phase induction motors, the starting torques produced are in the following descending order.

Accepted Answer

Capacitor-split, resistance-split, shaded pole

Answer

Resistor-split, capacitor-split, shaded pole

Answer

Shaded pole, resistor-split, capacitor split

Answer

Capacitor-split, resistor-split, shaded pole

Question 9

Which of the following statements associated with an ac series motor is incorrect?

Accepted Answer

Its torque-speed characteristic is similar to that of a dc shunt motor.

Answer

Its torque-speed characteristic is similar to that of a dc series motor.

Answer

Its power factor decreases with the increase in load torque.

Answer

Its speed falls with the increase in load torque.

Question 10

Speed of universal motor is

Accepted Answer

independent of frequency of supply.

Answer

proportional to frequency of supply.

Answer

proportional to square of frequency of supply.

Answer

inversely proportional to frequency of supply.

Question 11

A single phase reluctance motor

Accepted Answer

has salient pole rotor structure and runs at synchronous speed.

Answer

has salient pole rotor structure and runs at super-synchronous speed.

Answer

has salient pole rotor structure and runs at sub-synchronous speed,

Answer

has non-salient pole rotor structure and runs at synchronous speed.

Question 12

The torque of a reluctance motor can be effectively decreased by

Accepted Answer

decreasing the ratio of quadrature axis reluctance to direct axis reluctance

Answer

decreasing reluctance of the magnetic circuit along the quadrature axis

Answer

increasing reluctance of the magnetic circuit along the direct axis

Answer

increasing the ratio of quadrature axis reluctance to direct axis reluctance

Question 13

In a single phase hysteresis motor

Accepted Answer

starting torque is caused by both eddy current and hysteresis while the running torque is caused by hysteresis.

Answer

starting torque is caused by only eddy current while running torque is caused by only hysteresis.

Answer

starting as well as running torques are caused by both eddy current and hysteresis.

Answer

starting as well as running torques both are caused by only hysteresis.

Question 14

Match List-I (Type of motors) with List-ll (Application) and select the correct answer using the codes given below the lists:
List-I
A. Shaded pole motor
B. Reluctance motor
C. Universal motor
D. Single phase IM
List-ll
1. Ceiling fan
2. Food mixture
3. Timing and control purposes
4. Toys
Codes:
A B C D
(a) 4 3 2 1
(b) 2 3 1 4
(c) 3 4 2 1
(d) 2 1 3 4

Accepted Answer

(a)

Answer

(b)

Answer

(c)

Answer

(d)

Question 15

Which of the following single phase motor has no teeth or winding?

Accepted Answer

Hysteresis motor

Answer

Universal motor

Answer

Split-phase motor

Answer

Reluctance motor

Question 16

Match List-I (Type of motors) with List-ll (Characteristics) and select the correct answer using the codes given below the lists:
List-I
A. Shaded Pole motor
B. Hysteresis motor
C. PMDC motor
D. Capacitor start motor
List-ll
1. Least noise
2. Highest starting torque
3. Lowest speed
4. Used in cassette tape recorder
Codes:
A B C D
(a) 3 4 2 1
(b) 1 4 2 3
(c) 3 1 4 2
(d) 1 2 3 4

Accepted Answer

(c)

Answer

(a)

Answer

(b)

Answer

(d)

Question 17

Assertion (A): When a ceiling fan using a capacitor run motor is switched on, it hums but does not run. When it is driven by some external means it runs in the direction in which it was made to run.
Reason (R): The capacitor connected in series with the auxiliary winding is short circuited.

Accepted Answer

A is true but R is false.

Answer

Both A and R are true and R is a correct explanation of A.

Answer

Both A and R are true but R is not a correct explanation of A.

Answer

A is false but R is true.

Question 18

The rotor of a stepper motor has

Accepted Answer

neither a commutator, brushes nor winding

Answer

a commutator and no winding

Answer

a commutator and brushes only

Answer

a commutator and no brushes

Question 19

A stepping motor has four concentric coils on its 4-pole stator. It has an unwound variable reluctance motor with 5 teeth. The step angle for this motor is

Accepted Answer

18&deg;

Answer

36&deg;

Answer

9&ordm;

Answer

72&deg;

Question 20

A single phase induction motor is running at N rpm. Its synchronous speed is N_s. If its slip w.r.t forward field is s. What is the slip w.r.t. the backward field?

Accepted Answer

(2 - s)

Answer

s

Answer

- s

Answer

(1 - s)

GATE Electrical Engineering (EE) Test: Fractional KW Motors of Machines

MCQ Practice Test & Solutions: Test: Fractional KW Motors of Electrical Machines- 2 (20 Questions)

A single phase induction motor is

The capacitor in a capacitor-start induction run ac motor is connected in series with

Which of the following statements associated with shaded pole induction motor is incorrect?

Assertion (A) : Linear induction motor wide use in industry and electric traction.
Reason (R) : Linear induction motors are cheaper in initial as well as in maintenance costs.

In comparison to a resistance start motor, the capacitor start motor has
1. high starting torque
2. high running torque
3. larger phase difference between two winding currents
4. low starting current
Out of these, the correct answer is

The direction of rotation of a shaded pole induction motor

In various types of split-phase, 1-phase induction motors, the starting torques produced are in the following descending order.

Which of the following statements associated with an ac series motor is incorrect?

Speed of universal motor is

A single phase reluctance motor

The torque of a reluctance motor can be effectively decreased by

In a single phase hysteresis motor

Which of the following single phase motor has no teeth or winding?

Assertion (A): When a ceiling fan using a capacitor run motor is switched on, it hums but does not run. When it is driven by some external means it runs in the direction in which it was made to run.
Reason (R): The capacitor connected in series with the auxiliary winding is short circuited.

The rotor of a stepper motor has

A stepping motor has four concentric coils on its 4-pole stator. It has an unwound variable reluctance motor with 5 teeth. The step angle for this motor is

A single phase induction motor is running at N rpm. Its synchronous speed is N_s. If its slip w.r.t forward field is s. What is the slip w.r.t. the backward field?

GATE Electrical Engineering (EE) Mock Test Series 2027

GATE Electrical Engineering (EE) Mock Test Series 2027

Top Courses for Electrical Engineering (EE)

Schools

Competitive Exams

International Exams

Quick Links

About this Electrical Engineering (EE) Practice Test

Explore more Electrical Engineering (EE) Study Resources

GATE Electrical Engineering (EE) Test: Fractional KW Motors of Machines

MCQ Practice Test & Solutions: Test: Fractional KW Motors of Electrical Machines- 2 (20 Questions)

A single phase induction motor is

The capacitor in a capacitor-start induction run ac motor is connected in series with

Which of the following statements associated with shaded pole induction motor is incorrect?​

Assertion (A) : Linear induction motor wide use in industry and electric traction. Reason (R) : Linear induction motors are cheaper in initial as well as in maintenance costs.

In comparison to a resistance start motor, the capacitor start motor has 1. high starting torque 2. high running torque 3. larger phase difference between two winding currents 4. low starting current ​Out of these, the correct answer is

The direction of rotation of a shaded pole induction motor

In various types of split-phase, 1-phase induction motors, the starting torques produced are in the following descending order.

Which of the following statements associated with an ac series motor is incorrect?

Speed of universal motor is

A single phase reluctance motor

The torque of a reluctance motor can be effectively decreased by

In a single phase hysteresis motor

Which of the following single phase motor has no teeth or winding?

Assertion (A): When a ceiling fan using a capacitor run motor is switched on, it hums but does not run. When it is driven by some external means it runs in the direction in which it was made to run. Reason (R): The capacitor connected in series with the auxiliary winding is short circuited.

The rotor of a stepper motor has

A stepping motor has four concentric coils on its 4-pole stator. It has an unwound variable reluctance motor with 5 teeth. The step angle for this motor is

A single phase induction motor is running at N rpm. Its synchronous speed is Ns. If its slip w.r.t forward field is s. What is the slip w.r.t. the backward field?

GATE Electrical Engineering (EE) Mock Test Series 2027

GATE Electrical Engineering (EE) Mock Test Series 2027

Top Courses for Electrical Engineering (EE)

About this Electrical Engineering (EE) Practice Test

Explore more Electrical Engineering (EE) Study Resources

Which of the following statements associated with shaded pole induction motor is incorrect?

Assertion (A) : Linear induction motor wide use in industry and electric traction.
Reason (R) : Linear induction motors are cheaper in initial as well as in maintenance costs.

In comparison to a resistance start motor, the capacitor start motor has
1. high starting torque
2. high running torque
3. larger phase difference between two winding currents
4. low starting current
Out of these, the correct answer is

Assertion (A): When a ceiling fan using a capacitor run motor is switched on, it hums but does not run. When it is driven by some external means it runs in the direction in which it was made to run.
Reason (R): The capacitor connected in series with the auxiliary winding is short circuited.

A single phase induction motor is running at N rpm. Its synchronous speed is N_s. If its slip w.r.t forward field is s. What is the slip w.r.t. the backward field?