Planck's Law of Radiation

Physics

law

Planck's law of radiation

Planck's law describes the spectral density of electromagnetic radiation. These radiations are emitted by blackbody when they remain in thermal equilibrium at a given temperature.
This law gives the spectral distribution of radiation from a blackbody.

REVISE WITH CONCEPTS

What is Radiation?

ExampleDefinitionsFormulaes

Stefan Boltzmann Law

ExampleDefinitionsFormulaes

Special Distribution of Blackbody Radiation - Wien's Law

ExampleDefinitionsFormulaes

LEARN WITH VIDEOS

Important Questions

The temperature of equal masses of three different liquids and are and respectively. The temperature when and are mixed is and when and are mixed it is . What should be the temperature when and are mixed?

View solution
>

A black body at a temperature of radiates heat energy at the rate . At a temperature of , the rate of heat radiated per unit area in will be:

View solution
>

A body cools from C to C in minutes. Calculate the time it takes to cool from C to C. The temperature of the surroundings is C.

View solution
>

A spherical black body with a radius of 12cm radiates 450W power at 500K. If the radius were halved and the temperature doubled, the power radiated in watts would be :

View solution
>

State Kirchhoff's law of radiation and prove it theoretically.

View solution
>

Certain quantity of water cools from to in the first minutes and to in the next minutes. The temperature of the surroundings is ;

View solution
>

The plots of intensity versus wavelength for three black bodies at temperatures  and  respectively are shown in fig. Their temperatures are such that:

expand
View solution
>

A pan filled with hot food cools from to in minutes. When the room temperature is . How long will it cool from to ?

View solution
>

Two spheres of the same material have radii and and temperature and respectively. The energy radiated per second by the first sphere is :

View solution
>

A body cools down from to in Minutes when the temperature of surrounding is . The temperature of the body after next minutes will be:

View solution
>