Calculate the surface temperature of the planet,if the energy radiated by unit area in unit time is 5.67`**``10^(4)` watt

The earth receives solor radiation at a rate of 8.2Jcm^(-2)min^(-1) . Assuming that the sun radiates like a blackbody, calculate the surface temperature of the sun. The angle subtended by the sun on the earth is 0.53^(@) and the stefan constant sigma=5.67xx10^(-s)Wm^(-2)K^(-4) .

A black body at a temperature of 227^(@)C radiates heat energy at the rate of 5 cal/ cm^(2) -sec. At a temperature of 727^(@)C , the rate of heat radiated per unit area in cal/ cm^(2) -sec will be

An aluminiumum foil of relative emittance 0.1 is placed in between two concentric spheres at temperatures 300K and 200k respectively. Calculate the temperature of the foil after the steady state is reached . Assume that the spheres are perfect black body radiators. Also calculate the rater of energy transfer between one of the spheres and the foil. [sigma=5.67xx10^(-8) S.I. Unit]

Considering a wire of non-uniform cross-section as shown.If the area of cross-section at A is double of the area of cross-section at point B.Ratio of heat energy dissipated in a unit volume per unit time at points A and B is

The surface temperature of the sun is T_(0) and it is at average distance d from a planet. The radius of the sun is R . The temperature at which planet radiates the energy is

The surface area of a black body is 5xx10^(-4) m^(2) and its temperature is 727^@C . Energy radiated by it per minute is (Take sigma =5.67xx10^(-8) "J m"^(-2) s^(-1) K^(-4) )

Considering the sun as a perfect sphere of radius 6.8xx10^(8) m, calculate the energy radiated by it one minute. Take the temperature of sun as 5800 k and sigma = 5.7xx10^(-8) S.I. unit.

Calculate the equivalent energy in MeV of a unified atomic mass unit.

Calculate the temperature at which a perfect black body radiates at the rate of 1 W cm^(-2) , value of Stefan's constant, sigma = 5.67 xx 10^(-5) W m^(-2) K^(-8)

Two separate monochromatic light beams A and B of the same intensity (energy per unit area per unit time) are falling normally on a unit area of a metallic surface. Their wavelength are lambda_(A) and lambda_(B) respectively. Assuming that all the the incident light is used in ejecting the photoelectrons, the ratio of the number of photoelectrons from beam A to that from B is