An amount of water in an electric kettle reaches at its boiling point within 10 min. The same amount of water have to boil within 5min. Without changing heating coil and source To do this possible what should be the change of it?

Water boils in an electric kettle in 10 minutes after being switched on .How will you modify the heating coil to boil water is 5 minutes using the same source of power ?

An electric heating coil is connected in series with resistance of xOmega across the 240V mains, the coil being immersed in 1 kilogram of water at 20^@C. The temperature of the water rises to boiling point in 10 minutes. If the resistance x is short circuited, the time required to produce the same quantity of heat in 6 mins. Sb, the value of x is,

(i) The pressure and temperature of 0.8 g of He gas are 1 atm and 298 K respectively. If 400 J of heat is applied to the gas at constant volume, what will be change in internal energy and the final temperature of the gas ? (ii) If the same amount of heat is applied to the gas at constant pressure, then what will be the change in internal energy and the final temperature of the gas ? For both the cases, assume He gas behaves ideally and its C_(V)=(3)/(2)R .

Water equivalent of an electric kettle is 100 g. 890 g of water is taken in it, and it is then switched on. If water needs 3 min 45 s to reach its boiling point from and initial temperature of 20^(@)C , find the rate of production of heat by the kettle? (Assume that 20% of the energy produced is wasted.)

Latent heat of vaporisation of the water at normal boiling point is 40.75 kJmol^-1 . Calculate the change in entropy of vaporisation.

The time taken to heat certain amount of water from 0^@C to 100^@C in an electric kettle is 15 min and to evaporate it completely is 80 mins. Calculate the value of latent heat of .vapourisation?

What is the source of the heat that is needed for the water in the ponds near your house or the river to change in the same way?

A calorimeter of water equivalent 10 g contains 100 g of water at 90^(@)C . On exposure to air, its temperature falls to 80^(@)C in 5 min. If the same calorimeter is filled with 50 g of an oil, the time for the same drop in temperature is 2 min. Calculate the specific heat of the oil if the rate of heat loss in both the cases is assumed to be the same.