Analysis of a Three Phase Induction Motor Directly from Maxwell's   Equations
  The torque developed in a three phase AC squirrel cage motor is usually expressed in terms of resistances and reactances of the stator, the rotor, and the motor as a whole. We use Maxwell's equations to find the torque in terms of geometrical parameters. This allows us to estimate the torque developed by a motor without knowing the details of its circuitry. 
Shayak Bhattacharjee
physics.class-ph