Microwaves are used in

Infrared radiation was discovered in $1800$ by

Which of the following are not electromagnetic waves?

Which of the following rays has the maximum frequency?

$A$ source of power $4 \ kW$ emits $10^{20}$ photons in $1 \ s$. In which region of the electromagnetic spectrum does the emitted radiation lie?

Match List-$I$ with List-$II$.

List-$I$	List-$II$
$(a)$ $10\, km$ height over earth's surface	$(i)$ Thermosphere
$(b)$ $70\, km$ height over earth's surface	$(ii)$ Mesosphere
$(c)$ $180\, km$ height over earth's surface	$(iii)$ Stratosphere
$(d)$ $270\, km$ height over earth's surface	$(iv)$ Troposphere