Two spherical bodies have radii `R,2R` and emissivities e,2e If the temperature ratio is `2:1` then the powers will be in the ratio .

Two electric bulbs have filaments of lengths L and 2L diameters 2d and d and emissivities 3e and 4e If their temperatures are in the ratio 2:3 their powers will be in the ratio of .

Two Electric bulbs have filaments of lengths 1 and 21, diameters 2d and d. The emissivities of the bulbs are 3e, 4e with temperatures in the ratio 2 : 3. Their radiant powers will be in the ratio

Two bulbs have filaments of lengths, Emissi-vities and diameters in the ratio of 2 : 1. If ratio of their powers is 1 : 2 then, ratio of their temperatures is

Two spherical black bodies of radii R_(1) and R_(2) and with surface temperature T_(1) and T_(2) respectively radiate the same power. R_(1)//R_(2) must be equal to

Two spherical black bodies of radii R_(1) and R_(2) and with surface temperature T_(1) and T_(2) respectively radiate the same power. R_(1)//R_(2) must be equal to

Two spherical black bodies of radii R_(1) and R_(2) and with surface temperature T_(1) and T_(2) respectively radiate the same power. R_(1)//R_(2) must be equal to