Which of the following statements is correct?

One mole of diatomic gas having rotational modes only is kept in a cylinder with a piston system. The cross-section area of the cylinder is $4 \text{ cm}^2$. The gas is heated slowly to raise the temperature by $1.2^\circ\text{C}$ during which the piston moves by $25 \text{ mm}$. The amount of heat supplied to the gas is . . . . . . $J$. (Atmospheric pressure = $100 \text{ kPa}$, $R = 8.3 \text{ J/mol}\cdot\text{K}$) (Neglect mass of the piston)

An ideal gas is taken reversibly around the cycle $a-b-c-d-a$ as shown on the temperature $T$ - entropy $S$ diagram. The most appropriate representation of the above cycle on an internal energy $U$ - volume $V$ diagram is

An ideal monatomic gas of $n$ moles is taken through a cycle $W-X-Y-Z-W$ consisting of consecutive adiabatic and isobaric quasi-static processes,as shown in the schematic $V-T$ diagram. The volumes of the gas at $W, X,$ and $Y$ points are $64 \ cm^3, 125 \ cm^3,$ and $250 \ cm^3,$ respectively. If the absolute temperature of the gas $T_W$ at point $W$ is such that $nRT_W = 1 \ J$ ($R$ is the universal gas constant),then the amount of heat absorbed (in $J$) by the gas along the path $XY$ is $.....$

An ideal monoatomic gas is carried around the cycle $ABCDA$ as shown in the figure. The efficiency of the gas cycle is

Three samples $X, Y$,and $Z$ of the same gas have equal volumes and temperatures. The volume of each sample is doubled. The process is isothermal for $X$,adiabatic for $Y$,and isobaric for $Z$. If the final pressures are equal for the three samples,find the ratio of the initial pressures. (Take adiabatic exponent $\gamma = 3/2$)