When light propagates through a material medium of relative permittivity $\varepsilon_{ r }$ and relative permeability $\mu_{r^{\prime}}$ the velocity of light, $v$ is given by: (c - velocity of light in vacuum)

This question has Statement $-1$ and Statement $-2$ . Of the four choices given after the statements, choose the one that best describes the two statements

Statement $-1$ : Sky wave signals are used for long distance radio communication. These signals are in general, less stable than ground wave signals

Statement $-2$ : The state of ionosphere varies from hour to hour, day to day and season to season

A light wave is incident normally on a glass slab of refractive index $1.5$. If $4\%$ of light gets reflected and the amplitude of the electric field of the incident light is $30\, V/m$, then the amplitude of the electric field for the wave propagating in the glass medium will be.......$ V/m$

In an apparatus, the electric field was found to oscillate with an amplitude of $18 V/m. $ The magnitude of the oscillating magnetic field will be

The oscillating electric and magnetic vectors of an electromagnetic wave are oriented along

In a plane electromagnetic wave, which of the following has/ have zero average/value in one complete cycle?

$(a)$ Magnetic field

$(b)$ Magnetic energy

$(c)$ Electric field

$(d)$ Electric energy