Heat Questions

Which of the following circular rods, (given radius r and length l) each made of the same material and whose ends are maintained at the same temperature will conduct most heat ?

On a new scale of temperature (which is linear) called the $W$ scale, the freezing and boiling points of water are $39^{\circ }\text{W}$ and $239^{\circ }\text{W}$ respectively. What will be the temperature on the new scale corresponding to a temperature of $39^{\circ }\text{C}$ on the Celsius scale?

A thermodynamic system is taken through the cycle $ABCD$ as shown in figure. Heat rejected by the gas during the cycle is: