To make the motor revolve the key parameter is the torque which is the force applied to the shaft. But how the force is generated? A current flowing in an inductance or coil creates an electromagnet. The characteristics of the magnet depend on the current intensity and the direction. Two magnets will attract each other, north and south poles attract each other. The force to attract two magnets depends on the strength of the magnetic field, that depends on the current flawing through the coil. Therefore, in any condition, the torque will depend on the current. In other words, the amount of current controls the torque of a motor.