Explain the torque-slip characteristic of an induction motor.

Torque varies with slip in a characteristic curve. At zero slip (synchronous speed), torque is zero. Torque increases with slip to maximum (breakdown/pull-out torque) typically at 10-20% slip, then decreases. Starting torque occurs at slip=1 (standstill). Operating region is between no-load and breakdown torque where torque increases stably with slip. Beyond breakdown, torque decreases with increasing slip (unstable region), and motor stalls if load exceeds breakdown torque. Rotor resistance affects curve shape.