Answer
$Vo=IR$
When $Vo$ increases by a factor of 2, $I$ also increases by factor of 2.
Now since Power = $I^{2}R$, when current increases by factor of 2, power output becomes 4 times. Hence the hair dryer would quickly overheat and burn out.
Work Step by Step
$Vo=IR$
When $Vo$ increases by a factor of 2, $I$ also increases by factor of 2.
Now since Power = $I^{2}R$, when current increases by factor of 2, power output becomes 4 times. Hence the hair dryer would quickly overheat and burn out.
