Physics Test 77

Heat given to a body which raises its temperature by 1°C is :-

2 kg of ice at –20°C is mixed with 5kg of water at 20°C in an insulating vessel having a negligible heat capacity. Calculate the final mass of water in the vessel. It is given that the specific heat of water and ice are 1 kcal/kg-°C and 0.5 kcal/kg-°C respectively and the latent heat of fusion of ice is 80 kcal/kg:-

One g mol of a diatomic gas (γ = 1.4) is compressed adiabatically so that its temperature rises from 27°C  to 127°C  . The work done will be

A vessel contains a mixture of one mole of oxygen and two moles of nitrogen at 300 K. The ratio of the average rotational kinetic energy per O₂ molecule to that per N₂ molecule is:-

Two rigid boxes containing different ideal gases are placed on a table. Box A contains one mole of nitrogen at temperature 2T₀, while box B contains one mole of helium at temperature (7/3)T₀. The boxes are then put into thermal contact with each other, and heat flows between them until the gases reach a common final temperature (Ignore the heat capacity of boxes). Then, the final temperature of gases, T_f, in terms of T₀ is-

In solar spectrum fraunhoffer's lines are presents because :–