Thermodynamics ...

A body cools from $$71^0C$$ to $$69^0C$$ in $$4$$ minutes. If the surrounding temperature is constant at $$20^0C$$. Time taken by the body to cool from $$61^0C$$ to $$59^0C$$ is

Laplace told that this process is adiabatic
$$PV^r$$=const.
ditfrentiatiy c+ w.r.t v

A mixture of ideal gasses $$N_{2}$$ and $$He$$ are taken in the mass ratio of $$14 : 1$$ respectively. Molar heat capacity of the mixture at constant pressure is.

The molar heat capacity for an ideal gas cannot.

An ideal gas at $$27^{\circ}C$$ a gas is compressed adiabatically such that its pressure becomes $$(1/8)$$ of the original pressure. The final temperature will be $$(\gamma =\frac{5}{3})$$

One mole of an ideal monoatomic gas requires 207 J heat to raise the temperature by 10 K when heated at constant pressure. If the same gas is heated at constant volume to rise the temperature by the same 10 K, the heat required is [Given the gas constant R = 8.3 J/mol-K]

A mass of a gas at $$0^\circ$$ is expanded adiabatically so that its volume becomes 4 times the original the temperature of gas will fall :$$(\gamma = 1.5)$$

The molar heat capacity for an ideal gas 

Work done by a sample of an ideal gas in a process A is double the work done in another process B. The temperature rises through the same amount in the two processes. If $$ C_A \: and \: C_B $$ be the molar heat capacities for the two processes.

Two cyclic processes are shown on a P-V diagram. The working fluid is an ideal gas. Four points $$A,B,C$$ and $$D$$ are marked on the P-V diagram I and corresponding thermodynamic co-ordinates are given. Similarly, four points $$A',B',C'$$ and $$D'$$ are marked on the P-V diagram II. Here, the P and V scales are so chosen that these cycles on P-V diagram appear to be circular
Analyse these cycles on P-V diagram and answer the following question about these processes.
What is the net work done in the process I?