Mechanical power $($discussed in a previous unit$)$ is the rate at which work is done on an object. Electrical power is the rate at which work is done on a charge $($by the battery$)$ or on an electrical device $($by the charge$).$ In terms of an equation, it is $....($Fill in the numerator and the denominator.$)$

Power $=$

a$.$ A $60-$Watt light bulb uses up $q,$

b$.$ A $60-$Watt light bulb uses up $-q,$ J of energy when left on for $1$ hour $(3600$ s $).$

c$.$ A $1500-$Watt hair dryer uses up J of energy when left on for $4$ hours.

d$.$ A $120-$Watt fan uses up $q,J$ of energy when left on for a day.