The net work done by an ideal gas going through the cycle as shown in the $p-V$ diagram below is

A diatomic gas $\left(C_p=\frac{7}{2} R\right)$ does 200 J of work when it is expanded isobarically. The heat given to the gas in the process is

Statement I Gas thermometers are less sensitive than liquid thermometers.

Statement II The ratio of universal gas constant and avogadro's number is called Boltzmann's constant.

Statement III The density of a given mass of a gas at constant pressure is inversely proportional to its absolute temperature.

The correct option among the following is

Find the ratio of the length of a steel rod and a copper rod, if the steel rod is 4 cm longer, then the copper rod at any temperature.

(The coefficient of linear expansion for steel and copper are $1.1 \times 10^{-5} /{ }^{\circ} \mathrm{C}$ and $1.7 \times 10^{-5} /{ }^{\circ} \mathrm{C}$, respectively)