The spectrum of black body radiation is a ...... .

Three very large plates of the same area are kept parallel and close to each other. They are considered as ideal black surfaces and have very high thermal conductivity. The first and third plates are maintained at temperatures $2\ T$ and $3\ T$ respectively. The temperature of the middle (i.e.,second) plate under steady-state condition is

$A$ body is in thermal equilibrium with its surroundings. This is because .....

In which of the following phenomena do heat waves travel along straight lines with the speed of light?

The temperature of a blackbody radiation enclosed in a container of volume $V$ is increased from $100^{\circ} C$ to $1000^{\circ} C$. The heat required in the process is

$A$ thermopile bolometer is used to detect: