Move the slider "[b]STATOR ELECTRIC ANGLE[/b]" and see how the stator and rotor magnetic fields [math]M_s[/math] and [math]M_r[/math] rotate at the same speed. The rotor lags behind them (you can change the lagging by the slider [b]SLIP[/b], the higher the slip the slower the rotor. The rotor stops for [math]s=1[/math]. [br]Take notice that rotor current frequency is [math]s[/math] times the stator current one (see sinusoids at the left). For [math]s>1[/math] the rotor rotates backwards with respect to the magnetic field ([i]dissipative braking operation[/i]), for [math]s<0[/math] the rotor rotates faster than magnetic field ([math]generator\text{ }operation[/math]).