Answer
$(c) $ The temperature increases (the coil could even burn up).
Work Step by Step
At normal speed a Motor develops a back emf ε , so the induced current
$I = ( V - ε ) / R$
where R is the resistance of the motor
As the electric motor in a dryer is running at normal speed, the back emf is comparable with the applied emf and the motor draws a small current.
When the shaft of the motor stops turning, the back emf is zero. Therefore, the above equation becomes I = V / R and the current through the motor increases
As a result heat will be produced and the temperature of the coil will increase.
