The correct answer is: A. Capacitor start motor
A capacitor start motor is a type of single-phase induction motor that uses a capacitor to increase the starting torque. The capacitor is connected in parallel with the start winding, which creates a phase shift between the current in the start winding and the current in the run winding. This phase shift causes the magnetic field produced by the start winding to lag behind the magnetic field produced by the run winding. This lag in the magnetic fields creates a torque that helps the motor to start.
Capacitor start motors are used in applications where a high starting torque is required, such as in fans, pumps, and compressors.
The other options are incorrect because:
- A capacitor run motor uses a capacitor to improve the power factor of the motor. It does not provide a high starting torque.
- A split phase motor uses a capacitor to create a phase shift between the current in the start winding and the current in the run winding. However, the phase shift is not as great as in a capacitor start motor, so the starting torque is not as high.
- A shaded pole motor does not use a capacitor. It relies on the shading coil to create a phase shift between the current in the stator winding and the current in the rotor winding. The starting torque of a shaded pole motor is very low.