Questions in Electromagnetic Waves

Select	Question
	Which scientist experimentally proved the existence of electromagnetic waves
	An electromagnetic wave of frequency $\nu = 3.0\,MHz$ passes from vacuum into a dielectric medium with permitivity $\varepsilon = 4.0$. Then
	Frequency of a wave is $6 \times {10^{15}}Hz.$ The wave is
	The region of the atmosphere above troposphere is known as
	Which of the following electromagnetic waves have minimum frequency
	Which one of the following have minimum wavelength
	Radiations of intensity $0.5\,\,W/{m^2}$ are striking a metal plate. The pressure on the plate is
	Electromagnetic waves travel in a medium which has relative permeability 1.3 and relative permittivity 2.14. Then the speed of the electromagnetic wave in the medium will be
	The intensity of gamma radiation from a given source is I. On passing through 36 mm of lead, it is reduced to $\frac{I}{8}$. The thickness of lead which will reduce the intensity to $\frac{I}{2}$ will be
	If ${\lambda _v},\,{\lambda _r}$ and ${\lambda _m}$ represent the wavelength of visible light x-rays and microwaves respectively, then