Use the formula `lambda_mT=0.29cmK` to obtain the characteristic temperature ranges for different parts of the e.m. spectrum. What do the number that you obtain tell you?

Explanation

(a) Long distance radio broadcasts use shortwave these can be refracted by the inosphere.
(b) It is necessary to use satellites for long distance TV transmissions because television signals are of high frequencies and high energies. Thus, these signals are not reflected by the ionosphere, Hence, satelites are helpful in reflecting TV signals. Aslo, they help in long distance TV transmissions.
(c) With reference to x-ray astronomy, X-rays are absorbed by the atmospehre However, visible and radio waves can penetrate it. Hence, optical and radio telescopes are built on the ground , whilte x-ray astronomy is possible only with the help of satellites orbiting the Earth.
(d) The small ozone layer on the top of the atmosphere is crucial for human survival because it absorbs harmful ultraviolet radiations present in sunlight and prevents it from reaching the Earth's surface.
(e) In theabsenceof an atmosphere, there would be no greenhouse effect on the surface of the Earth. as a result, the temperature of the Earth would decrease rapidly, making it chilly and difficult for human survival.
(f) A global nuclear war on the sruface of the Earth would have disastrous consequences.
post nucelar war, the Earth will experience severe winter as the war will produce clouds of smoke that would cover maximum parts of the sky, tehreby preventing solar light fform reaching the atmospehre, Also, it will lead to the depletion of the ozone layer.