If `lambdam` for solar radiation is `4753A^@`, estimate the surface temperature of the sun. Wien's constant, b = 0.2893 cmk.

Calculate the value of lambda_max for solar radiation assuming that surface temperature of Sun is 5800 K (b = 2.897 xx 10^-3 mK ). In which part of the electromagnetic spectrum, does this value lie?

Assuming that the sun radiates as a black body, calculate the energy radiated per minute by unit area of its surface. Surface temperature of the sun = 5727^@C and Stefan's constant = 5.7 xx10^-8 Jm^-2K^-4s^-1 .

The intensity of radiation emitted by the sun has its maximum value at a wavelength of 510 nm and that emitted by the North star has the maximum value at 350 nm. If these stars behave like black bodies, then the ratio of the surface temperatures of the sun and the north star is

A 100 watt filament loses all its power by radiation when it is heated to a temperature of 2500 K. If the diameter of the filament is 0.2 mm and the surface emissivity of the filament is 0.5, find the length of the filament. (Stefan's constant sigma = 5.67 xx10^-8 W/m^2k^4 )

The surface of a black body is at a temperature 727^(@)C and its cross section is 1m^(2) Heat radiated from this surface in one minute in Joules is (Stefan's constant =5.7 xx 10^(-8) W//m^(2)//k^(4)) .

Analysis of the sun's spectrum shows that the wave length of maximum intensity is 4750 A^@ . Taking Wien's constant as 2.9 xx 10^-3 mk , find the surface temperature of the sun.

A 60 watt filament lamp loses all its energy by radiation from its surface. The emissivity of the surface is 0.5. The area of the surface is 5 xx 10^-5m^3 . Find the temperature of the filament ( sigma = 5.67 xx 10^-8m^2s^-4K^-4 )

A body having a surface area of 50cm^2 radiates 300J of energy per minute at a temperature of 727^(@)C . The emissivity of the body is ( Stefan's constant =5.67xx10^(-8)W//m^2K^4 )