A cobalt specimen emits induced radiation of 75.6 millicurie per second. Convert this disintegration into becquerel.
(one curie = `3.7xx10^(10) Bq`)

A radon specimen emits radiation of 3.7xx10^(3)GB q pe second. Convert this disintegration in terms of curie. (one curie =3.7xx10^(10) disintegration per second)

Assume that the total surface area of a human body is 1.6m^(2) and that it radiates like an ideal radiator. Calculate the amount of energy radiates per second by the body if the body temperature is 37^(@)C . Stefan constant sigma is 6.0xx10^(-8)Wm^(-2)K^(-4) .

A RADAR signal is beamed towards a planet and its echo is received 7 minutes later. If the distance between the planet and the Earth is 6.3 xx 10^(10) m. Calculate the speed of the signal.

One end of a rod length 20cm is inserted in a furnace at 800K. The sides of the rod are covered with an insulating material and the other end emits radiation like a blackbody. The temperature of this end is 750K in the steady state. The temperature of the surrounding air is 300K. Assuming radiation to be the only important mode of energy transfer between the surrounding and the open end of the rod, find the thermal conductivity of the rod. Stefan constant sigma=6.0xx10^(-1)Wm^(-2)K^(-4) .