The rates of heat radiation from two patches of skin each of area A on a patient's chest differ by `2%` If the patch of the lower temp is at `300K` and emissivity of both the patches is assumed to be unity, the temp of other patch would be .

The rate of heat radiation from two patches of skin each of area S, on a patient's chest differ by 2%. If the patch of the lower temperature is at 300 K and the emissivity of both the patches is assumed to be unity, the temperature of the other patch is closest to

There is a temperature difference of 1K between two black patches of skin on patient's chest and each patch having area A The radiant heat emitted from them is differ by 2% then temperature of two patches may be .

A plane surface A is at a constant temperature T_(1) = 1000 K . Another surface B parallel to A, is at a constant lower temperature T_(2) = 300 K . There is no medium in the space between two surfaces. The rate of energy transfer from A to B is equal to r_(1)(J/s) . In order to reduce rate of heat flow due to radiation, a heat shield consisting of two thin plates C and D, thermally insulated from each other, is placed between A and B in parallel. Now the rate of heat transfer (in steady state) reduces to r_(2) . Neglect any effect due to finite size of the surfaces, assume all surfaces to be black bodies and take Stefan’s constant sigma = 6 xx 10^(- )8 Wm^(- 2)K^(-4) . Area of all surfaces A = 1m^(2) . (i) Find r^(1) (ii) Find the ratio (r^(2))/(r^(1)) (iii)Find the ratio (r^E(2))/(r_(1)) if temperature of A and B were 2000 K 600 K respectively.

The figure indicates three small patches 1, 2, and 3 that lie on the surfaces of two imaginary spheres, the spheres are centered on an isotropic point source S of sound. The rates at which energy is transmitted through the three patches by the sound waves are equal. Rank the patches according to (a) the intensity of the sound on them and (b) their area, greatest first.