A four-pole, three-phase motor contains how many coils?

In a four-pole, three-phase motor, it contains twelve coils. This is because the number of coils is determined by the formula: the total number of poles multiplied by the number of phases, divided by two.

For a three-phase system, each phase typically requires two coils to produce one complete cycle of the magnetic field. The four poles in the motor create four separate magnetic fields, requiring two coils for each pole. Therefore, the calculation follows as:

4 poles × 3 phases = 12 coils.

This configuration ensures that each coil contributes to the overall magnetic field necessary for the motor's operation, providing sufficient torque and maintaining the phase differences required for effective performance. This is why the correct answer is twelve.