Answer
See below.
Work Step by Step
The windings of the electric motor draw a small current when the motor is operating.
Two sources of this current must be addressed. First is the current input into the windings that turns the armature (the motor effect). Second, the rotation of the windings in the magnetic field of the motors induces an oppositely directed current (the generator effect). That means that the net current is small.
When the motor suddenly jams and the armature stops rotating, the net current spikes upward because the second contribution, the generated current, suddenly disappears. This can overheat the motor.