An induction motor has slip at maximum torque = 0.2. If rotor resistance is doubled, new slip is:

Option 1: 0.1

Option 2: 0.2

Option 3: 0.4

Option 4: 0.8

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Correct Option: 3

Explanation

Slip at maximum torque is directly proportional to rotor resistance. Doubling rotor resistance doubles slip from 0.2 to 0.4.