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1) The torque developed by a 3-phase induction motor is approximately proportional to
A) √s
B) s^2
C) s
D) 1/s
Ans:C
2) The starting torque of a 3-phase induction motor varies as
A) V^2
B) V
C) √V
D) 1/V
Ans:A
3) The starting torque of a squirrel cage induction motor is
A) very large
B) very low
C) slightly more than full load torque
D) zero
Ans:C
4) Insertion of resistance in the rotor circuit of an induction motor to develop a given torque causes............... in rotor current
A) almost no change
B) increase
C) decrease
D) none of these
Ans:A
5) In an induction motor, maximum torque varies as
A) V/X2
B) V^2/X2
C) V/R2
D) V/X^2
Ans:B
6) In an induction motor if the flux density is reduced to one-half of its normal value then the torque will
A) reduce to one half
B) reduce to one fourth
C) remain unchanged
D) none of these
Ans:A
7) In a 3-phase slip ring induction motor high starting torque is achieved by
A) increasing supply voltage V
B) increasing supply frequency f
C) connecting a capacitor across the motor terminals
D) connecting a star-connected resistance across the slip ring terminals of the motor
Ans:D
8) For a constant torque load, the supply voltage of a squirrel cage induction motor is reduced by a factor of 1/√2, its rotor current is modified by a factor
A) 2
B) 1/√2
C) √2
D) none
Ans:C
9) In a 3-phase induction motor, the maximum torque
A) is independent of rotor circuit resistance
B) varies as rotor resistance
C) varies as the square of rotor resistance
D) varies inversely as rotor circuit resistance
Ans:A
10) For a slip-ring induction motor, if the rotor resistance is increased, then
A) starting torque and efficiency incrreases
B) starting torque decrease but efficiency increases
C) starting torque increase but efficiency decreases
D) starting torque and efficiency decrease
Ans:C
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1) The torque developed by a 3-phase induction motor is approximately proportional to
A) √s
B) s^2
C) s
D) 1/s
Ans:C
2) The starting torque of a 3-phase induction motor varies as
A) V^2
B) V
C) √V
D) 1/V
Ans:A
3) The starting torque of a squirrel cage induction motor is
A) very large
B) very low
C) slightly more than full load torque
D) zero
Ans:C
4) Insertion of resistance in the rotor circuit of an induction motor to develop a given torque causes............... in rotor current
A) almost no change
B) increase
C) decrease
D) none of these
Ans:A
5) In an induction motor, maximum torque varies as
A) V/X2
B) V^2/X2
C) V/R2
D) V/X^2
Ans:B
6) In an induction motor if the flux density is reduced to one-half of its normal value then the torque will
A) reduce to one half
B) reduce to one fourth
C) remain unchanged
D) none of these
Ans:A
7) In a 3-phase slip ring induction motor high starting torque is achieved by
A) increasing supply voltage V
B) increasing supply frequency f
C) connecting a capacitor across the motor terminals
D) connecting a star-connected resistance across the slip ring terminals of the motor
Ans:D
8) For a constant torque load, the supply voltage of a squirrel cage induction motor is reduced by a factor of 1/√2, its rotor current is modified by a factor
A) 2
B) 1/√2
C) √2
D) none
Ans:C
9) In a 3-phase induction motor, the maximum torque
A) is independent of rotor circuit resistance
B) varies as rotor resistance
C) varies as the square of rotor resistance
D) varies inversely as rotor circuit resistance
Ans:A
10) For a slip-ring induction motor, if the rotor resistance is increased, then
A) starting torque and efficiency incrreases
B) starting torque decrease but efficiency increases
C) starting torque increase but efficiency decreases
D) starting torque and efficiency decrease
Ans:C
If you like this post please share it with your friends and comment here if you have any doubts...
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