Induction Motor

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Q1:- In a 3- phase induction motor the current is produced in the rotor conductors by 

1. giving a.c. supply 
2. giving dc supply 
3. induction effect 
4. none of these

ANSWER:- 3

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Q2:-In a 3-phase induction motor slip for maximum torque , in terms of rotor resistance r2

1. independent of r2
2. directly proportional to 2
3. inversely proportional to r2
4. none of these

ANSWER:-2

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Q3:-If any two phase of the three phase supply are interchange motor will

1. run in the same direction 
2. stop running 
3. run in the reverse direction 
4. draw high current 

ANSWER:-3

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Q4:-At full load the current induced int he rotor conductor of a 3- phase squirrel cage induction motor is 

1. more than rated current 
2. less than rated current 
3. nearly equal to rated current 
4. none of these 

ANSWER:-3

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Q5:-The frequency of the induced emf in the rotor circuit is 

1. maximum at stand still 
2. zero at stand still
3. maximum at synchronous speed
4. none of these.

ANSWER:-1

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