Question

In an Induction motor, the rotor copper loss is equal to

• A. Slip \(\times\) rotor input power
• B. \((1-\text{slip})\times\) rotor input power
• C. Rotor input power/slip
• D. Slip\(^2\times\) rotor input power

Hint:

In an induction motor, rotor copper loss \(=sP_2\), and mechanical power developed \(=(1-s)P_2\).

Answer 1

The Correct Option is A

Concept: In an induction motor, air-gap power or rotor input power is divided into rotor copper loss and mechanical power developed.

Step 1: Let rotor input power be: \[ P_2 \]

Step 2: Rotor copper loss is: \[ P_{\text{cu}}=sP_2 \] where \(s\) is slip.

Step 3: Mechanical power developed is: \[ P_m=(1-s)P_2 \]

Step 4: Therefore, rotor copper loss is: \[ \boxed{\text{Slip}\times \text{rotor input power}} \]