A system $S$ receives heat continuously from an electrical heater of power $10W$. The temperature of S becomes constant at $50^o C$ when the surrounding temperature is $20^o C$. After the heater is switched off, $S$ cools from $35.1^o C$ to $34.9^o C$ in $1$ minute. The heat capacity of $S$ is…….. $ J/^oC$

By what the temperature difference can be determined if the state of substance is not changed for the absorption of given heat ?

A $10\, kW$ drilling machine is used to drill a bore in a small aluminium block of mass $8.0\, kg .$ How much is the rise in temperature of the block in 2.5 minutes, assuming $50\, \%$ of power is used up in heating the machine itself or lost to the surroundings. Specific heat of aluminium $=0.91\,J\,g^{-1}\,K^{-1}$ 

A water fall is $84$ metres high. If half of the potential energy of the falling water gets converted to heat, the rise in temperature of water will be

$0.93$ $watt-hour$ of energy is supplied to a block of ice weighing $10\,gm.$ It is found that