Four situations are shown in List-I. Match each situation to the corresponding relation between heat energy and temperature in List-II. List-I List-II (P) A and B are equal-sized spheres in an isother

Question

Four situations are shown in List-I. Match each situation to the corresponding relation between heat energy and temperature in List-II.

List-I	List-II
(P) A and B are equal-sized spheres in an isothermal chamber at equilibrium temperature $T_{0}$ . A is black; B is gray with emissivity 0.8. Consider steady state.	(1) $T_{A} > T_{B}$ or $T_{A} = T_{B}$
(Q) Spectral emissive power versus wavelength for equal-area black bodies A and B:	(2) $T_{A} < T_{B}$
(R) A solid sphere A is connected to a power source inside a thick spherical shell B. Both surfaces are perfect black bodies at steady state.	(3) Heat energy radiated by A is greater than B.
(S) Large black plates (1) and (2) are maintained at $T_{1}$ and $T_{2}$ , with $T_{1} > T_{2}$ . A and B are large plates of emissivity 1. Consider steady state.	(4) Heat energy radiated by B is greater than A.

TestHub · Accepted Answer

For P, the sphere temperatures in the isothermal chamber are equal at equilibrium.

$T_{A} = T_{B} = T_{0}$

A has higher emissivity, so its radiated power is greater: P → 3,1.

For Q, the peak for B occurs at a shorter wavelength.

$T_{B} > T_{A}$

With equal surface areas, B radiates more: Q → 2,4.

For R, heat flows from the powered inner sphere A to shell B.

$T_{A} > T_{B}$

Therefore R → 1.

For S, heat flows from the hotter surface (1) toward surface (2).

$T_{A} > T_{B}$

Therefore S → 1. The printed code is (B).

Physics - Heat & Thermo Question with Solution | TestHub