An electric heater of power 1000 W raises the temperature of 5 kg of a liquid from 25 to 31 degrees celsius in 2 minutes. calculate heat capacity of the liquid and its specific heat.

Calculate the number of kJ of heat neccesary to raise the temperature of 60.0g of aluminum from 35^(@) C to 55^(@)C . Molar heat capacity of Al is 24 J mol^(-1) k^(-1) .

An electric heater of resistance 8 Omega draws 15 A from service mains for 2 hour,Calculate the rate at which heat is developed in the heater.

A coper block of mass 2.5 kg is heated in a furnace to a temperature of 500 ^@C and then placed on a large ice block. What is the maximum amount of ice that can melt? (specific heat of copper = 0.39 J g^-1 C^-1 , heat of fusion of watter = 335 J g^-1 ).

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 ^@C^-1

The Sun is a hot plasma (ionized matter) with its inner core at a temperature exceeding 107 K, and its outer surface at a temperature of about 6000 K. At these high temperatures, no substance remains in a solid or liquid phase. In what range do you expect the mass density of the Sun to be, in the range of densities of solids and liquids or gases ? Check if your guess is correct from the following data : mass of the Sun = 2.0 xx 10^30 kg , radius of the Sun = 7.0 xx 10^8 m .

0.32 g of oxygen is kept in a rigid container and is heated .Find the heat energy needed to raise the temperature from 25^@C to 35^@C .The molar heat capacity of oxygen at constant volume is 20 J mol^(-1) K^(-1) .

Calculate the heat of combustion of coal when 10 g of coal on burning raises the temperature of 2 litres of water from 20^@C to 55^@C .

Calculate the electric field and magnetic field produced by the rediation coming from a 100 W bulb at a distance of 3 m. Assume that the efficiency of the bulb is 2.5 % and it is a point source.