Thermal Propert...

The temperature of sun is 5500 K and it emits maximum intensity radiation in the yellow region (5.5 × 10^–7 m). The maximum radiation from a furnace occurs at wavelength 11 × 10^–7 m. The temperature of furnace is

The surface temperature of the sun is

A metal ball of surface area 200 cm² and temperature 527^oC is surrounded by a vessel at 27^oC. If the emissivity of the metal is 0.4, then the rate of loss of heat from the ball is (σ = 5.67 × 10^–8 J/m²–s–K⁴)

The temperature of a piece of iron is 27^oC and it is radiating energy at the rate of Q kWm^–2. If its temperature is raised to 151^oC, the rate of radiation of energy will become approximately

The temperature of two bodies A and B are 727^oC and 127^oC. The ratio of rate of emission of radiations will be

The temperature at which a black body of unit area loses its energy at the rate of 1 joule/second is

The tungsten filament of an electric lamp has a surface area A and a power rating P. If the emissivity of the filament is ϵ and σ is Stefan\'s constant, the steady temperature of the filament will be

A thin square steel plate with each side equal to 10 cm is heated by a blacksmith. The rate of radiates energy by the heated plate is 1134 W. The temperature of the hot steel plate is (Stefan\'s constant σ = 5.67 × 10^–8 watt m^–2K^–4, emissivity of the plate = 1)

The energy emitted per second by a black body at 27^oC is 10 J. If the temperature of the black is increased to 327^oC, the energy emitted per second will be

A spherical black body with a radius of 12 cm radiates 440 W power at 500 K. If the radius were halved and the temperatures doubled, the power radiated in watt would be