Thermodynamics ...

Two rods P and Q have equal lengths. Their thermal conductivities are K₁ and K₂ and cross sectional areas are A₁ and A₂. When the temperature at the ends of each rod are T₁ and T₂ respectively, the rate of flow of heat through P and Q will be equal, if

A surface at temperature T₀K receives power P by radiation from a small sphere at temperature T > T₀ and at a distance d. If both T and d are doubled, the power received by the surface will become

Two circular discs A and B with equal radii are blackened. They are heated to same temperature and are cooled under identical conditions. What inference do you draw from their cooling curves, Fig.?

Two identical square rods of metal are welded end to end as shown in Fig. (a). 20 cals of heat flow through this combination in 4 minutes. If the rods were welded as shown in Fig.(b), the same amount of heat will flow through the rod in

The frequency (V_m) corresponding to which energy emitted by a black body is maximum may vary with temperature T of the body as shown in Fig. Which of the curves represents correct variation.

Heat energy absorbed by a system in going through a cyclic process shown in Fig. is

Two samples, A and B, of a gas at the same initial temperature and pressure are compressed from volume V to V/2; A isothermally and B adiabatically. The final pressure of A will be

The coefficient of thermal conductivity of copper is nine times that of steel. In the composite cylindrical bar shown in Fig., what will be the temperature at the junction of copper and steel?

A monoatomic ideal gas, initially at temperature T₁ is enclosed in a cylinder fitted with a frictionless piston. The gas is allowed to expand adiabatically to a temperature T₂ by releasing the piston suddenly. If L₁, L₂ are the lengths of the gas column before and after expansion respectively, then T₁/T₂ is given by

The plots of intensity versus wavelength for three black bodies at temperatures T₁, T₂, T₃ respectively are shown in Fig. Their temperatures are such that