Two wires of the same material and length but different cross-sectional areas are connected in series across a battery. If the ratio of their radii is 2:1, what is the ratio of the power dissipated in them?

How many calories of heat will be produced approximately in a ${\rm{210}}\,\,{\rm{W}}$ electric bulb in ${\rm{5}}\,\,{\rm{min}}$ ?

Heat produced (cals) in a resistance $R$ when a current $I$ amperes flows through it for $t$ seconds is given by the expression

A $12\,\,HP$ motor has to be operated $8\,\,h/day$. How much will it cost at the rate of $50\,\,paise/kWh$h in $10\,\,days\,\,?$

In a house there are 4 bulbs each of $50W$ and 5 fans each of $60W$. If they are used at the rate of 6 hours a day, the electrical energy consumed in a month of 30 days is

How much energy in kilowatt hour is consumed in operating ten ${\rm{50}}\,\,{\rm{watt}}$ bulbs for ${\rm{10}}\,\,{\rm{hours}}$ per day in a month (${\rm{30}}\,\,{\rm{days}}$)

In a house there are 4 bulbs each of $50W$ and 5 fans each of $60W$. If they are used at the rate of 6 hours a day, the electrical energy consumed in a month of 30 days is

A 100W bulb operates for 10 hours. The energy consumed is: