Suppose that a magnetic force in a motor was not strong enough to move. Describe how the force could be made stronger so that the motor would work?

If a motor does not turn, the rotor/and or the stator current needs to be increased to increase the magnetic force. Motor damage/or failure is likely if you much exceed the design current for the motor. Options are reduce the torque required by the load and/or replace the motor with one with more starting torque.