In a capacitor start single phase induction motor the current in the:

• A. Starting winding leads the voltage
• B. The main winding leads the voltage
• C. Supply lines lead the voltage
• D. Starting winding lags the voltage

Answer: (A)

In the capacitor start, single-phase induction motor the capacitor is connected in series with the starting auxiliary winding. In this manner, the current in the starting winding may be made to lead the line voltage. Since the running winding current lags the line voltage, the phase displacement between the two currents is made to approximately 90° on starting.
Placing the capacitor in the auxiliary winding circuit to produce a greater phase difference between the current in the main and the auxiliary windings. Due to greater phase difference capacitor Start motors have very high starting torque for a single-phase AC motor.