Electrical Machine - II (3150910) MCQs

MCQs of Induction Machines

Showing 71 to 80 out of 95 Questions
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71.

What is the main role of the starter in 3-phase Induction Motor?

(a)

To limit High Starting Current
(b)

To provide Overload and Under-voltage Protection
(c)

To produced Starting Torque
(d)

To limit the speed 
Answer:

Option (a)

72.

What is the role of the starter in 3-phase Induction Motor? 

(a)

To limit Heavy starting current
(b)

To provide Overload and Under-voltage Protection
(c)

To avoid malfunctioning produces due to a large voltage drop in the line
(d)

All of these
Answer:

Option (d)

73.

Due to which of the following, The high starting current is flow in the 3-Phase Induction Motor?

(a)

At starting, S=1
(b)

At Starting, Eb=0  (Back EMF in rotor winding)
(c)

At Starting, E1=0  (induced EMF of Stator winding)
(d)

All of the above
Answer:

Option (a)

74.

Which of the following method used to limit heavy starting current in 3-Phase squirrel Cage Induction Motor?

(a)

By Increasing Rotor Resistance
(b)

By Reducing Stator Frequency
(c)

By reducing Stator Voltage
(d)

All of these
Answer:

Option (c)

75.

Which of the following 3-Phase Induction Motor Starter can not control Heavy Starting Current?

(a)

Primary resistors (or rheostat) or reactors
(b)

Auto-transformer (or auto starter)
(c)

Direct-on-line (DOL) starter
(d)

Star-delta starter
Answer:

Option (c)

76.

In Primary Resistors (or rheostat) or reactors starter, Externel Resistor is Connected ______________

(a)

Externally connected through Slip Ring
(b)

between rotor winding & Slip
(c)

between Stator winding & Line
(d)

between Rotor winding & Line
Answer:

Option (c)

77.

Starting Line Current & Starting Motor Current is reduced by the factor ____________ & _________ respectively in Auto-transformer starter.

(a)

X   &   X2
(b)

X2  &   X
(c)

𝟏/√𝟑   &   𝟏/𝟑
(d)

X   &   X
Answer:

Option (b)

78.

Starting Line Current & Starting Motor Current is reduced by the factor ____________ & _________ respectively in Star-Delta starter.

(a)

X   &   X2
(b)

X2  &   X
(c)

𝟏/√𝟑   &   𝟏/√𝟑
(d)

𝟏/√𝟑   &   𝟏/𝟑
Answer:

Option (c)

79.

What is/are the advantages of Rotor Resistors Starter compared to other IM starters?

(a)

Starting PF & torque is increased
(b)

Can be started on heavy load
(c)

Motor acceleration quickly
(d)

All of these
Answer:

Option (d)

80.

Which of the following phenomena will happen during the breaking period?

(a)

The motor came at standstill
(b)

negative torque will be produced in the motor
(c)

Kinetic energy stored by the motor is converted into Heat or Electrical Energy
(d)

All of these
Answer:

Option (d)

Showing 71 to 80 out of 95 Questions
5 6 7 8 9 10