Blackbody Radiation

What is spectral energy density?

What does the spectral density tell us?

What is spectral density of radiation?

What is the difference between energy spectral density and power spectral density?

Why energy spectral density is important?

What is the formula for emissive power?

Is absorptive power and emissivity same?

What is the spectral absorptive power?

In Raman effect, the spectral line with lower frequency than the incident frequency is

A certain planet is at $a$ distance $d$ from the sun. Then the temperature of the planet is

Heat radiations propagate with the speed of

Which of the following statement is correct

Three large identical plates are kept parallel to each other. The outer two plates are maintained at temperatures $T$ and $2T$, respectively. The temperature of the middle plate in steady state will be close to

The spectra of a black body at temperature $327 °\mathrm{C}$ and $627 °\mathrm{C}$ are shown in figure. If $A_{1 }$ and $A_2$ be the areas under the two curves respectively, the value of $A_2/A_1$ is :-

A good absorber is

Find the amount of energy transmitted, if $150 \mathrm{J}$ of energy is incident on area of $2 {\mathrm{m}}^2$. Given $Q_r= 15 \mathrm{J}$ and coefficient of absorption is $0.6$.

A piece of blue glass heated to a high temperature and a piece of red glass at room temperature are taken inside a dimly-lit room. Then,

The number of photons falling per second on a completely darkened plate to produce a force of $6.62\times {10}^{-5} N$ is $n$. If the wavelength of the light falling is $5\times {10}^{-7} \mathrm{m},$ then $n=\dots \times {10}^{22}.\left(h=6.62\times {10}^{-34}\mathrm{ J}-\mathrm{s}\right)$

The surface of a black body is at a temperature ${727}^{ \mathrm{o}}\mathrm{C}$ and its cross section is $1\mathrm{ }{\mathrm{m}}^2$ . Heat radiated from this surface in one minute in joules is (Stefan's constant $5.7\times {10}^{-8} \mathrm{W} {\mathrm{m}}^{-2} {\mathrm{K}}^{-4}$ )

Microwave oven acts on the principle of: