Kinetic Theory of Gases and Radiation Quiz 3

Which of the following substances is opaque to radiant energy?

The substance which allows heat radiations to pass through it is

A perfect blackbody is the one that

The conical projection in Fery’s blackbody is

The emissive power of a body is

The dimensions of emissive power are

The emissive power per wavelength interval $E _\lambda$ of a blackbody at an absolute temperature $T_1$ is maximum at $\lambda_1$ = 1.1 µm. At an absolute temperature $T_2$ , its $E_\lambda$ is maximum at $\lambda_2$ = 0.55 µm. Then, $\frac{T_1}{T_2}$ is equal to

The temperature of the photosphere of the Sun is about 6000 K. Wien’s displacement law constant is 2.898 × $10^{-3}$ m.K. The photosphere has maximum emissive power at wavelength

A sphere and a cube made of the same metal have equal volumes, identical surface characteristics and are at the same temperature. If they are allowed to cool in identical surroundings, the ratio of their rates of loss of heat will be

If the absolute temperature of a blackbody is increased by a factor 3, the energy radiated by it per unit time per unit area will increase by a factor of