Radiation

The spectrum of thermal radiation contains:

List the gases responsible for the greenhouse effect.

Sun's radiant energy is utilized by

Which of the following statement is correct

What are greenhouse gases? List some examples.

Which of the following gases is responsible for greenhouse effect?

A device in which heat measurement can be done is called a _____.

The rate of cooling at $600 \mathrm{K}$, if surrounding temperature is $300 \mathrm{K}$ is $H$. The rate of cooling at $900 \mathrm{K}$ is

If the temperature of the Sun were to increase from $T$ to $2T$ and its radius from $R$ to $2R$. The ratio of power radiated by it would become

Two spheres of the same material have radii $1 \mathrm{m}$ and $4 \mathrm{m}$ and temperature $4000 \mathrm{K}$ and $2000 \mathrm{K}$ repectively. The energy radiated per second by the first sphere is

The temperature of a radiating body increases by $30\%$. Then, the increase in the amount of radiation is

The wavelength of maximum intensity of radiation emitted by a star is $289.8\mathrm{ }\mathrm{n}\mathrm{m}$. The radiation intensity of the star is
(Stefan's constant $=5.67\times {10}^{-8} \mathrm{W} {\mathrm{m}}^{-2} {\mathrm{K}}^{-4},$Wien's constant $=b=2898\mathrm{ }\mathrm{\mu }\mathrm{m}\mathrm{ }\mathrm{K}$) 

Experimental investigation shows that the intensity of solar radiation is maximum for a wavelength $480 \mathrm{nm}$ in the visible region. Estimate the surface temperature of sun. (Given Wien's constant $b=2.88\times {10}^{-3} \mathrm{m}\mathrm{ }\mathrm{K}$)

Three very large plates of 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 temperature $2T$ and $3T$ respectively. The temperature of the middle ( i.e. second) plate under steady state condition is

The earth radiates in the infra-red region of the spectrum. The spectrum is correctly given by

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,

According to Wien's law

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 $5.7\times {10}^{-8} \mathrm{W} {\mathrm{m}}^{-2} {\mathrm{K}}^{-4}$ )

The ratio of energies of emitted radiation by a black body at $600 \mathrm{k}$ and $900 \mathrm{k}$, when the surrounding temperature is $300 \mathrm{k}$, is

Following graphs show the variation in the intensity of heat radiations by the black body and frequency at a fixed temperature. Choose the correct option.