In a plane electromagnetic wave travelling in free space, the electric field component oscillates sinusoidally at a frequency of $2.0 \times 10^{10} \text{ Hz}$ and amplitude $48 \text{ V m}^{-1}$. Then the amplitude of the oscillating magnetic field is: (Speed of light in free space $= 3 \times 10^8 \text{ m s}^{-1}$)

The energy of the EM wave is of the order of $15 \text{ keV}$. To which part of the spectrum does it belong?

Light with an average flux of 20 W/cm² falls on a non-reflecting surface at normal incidence having a surface area of 20 cm². The energy received by the surface during a time span of 1 minute is:

The ratio of the amplitude of the magnetic field to the amplitude of electric field for an electromagnetic wave propagating in vacuum is equal to:

A parallel plate capacitor is charged by connecting it to a battery through a resistor. If $i$ is the current in the circuit, then in the gap between the plates:

In an electromagnetic wave in free space the root mean square value of the electric field is $E_{rms} = 6$ V/m. The peak value of the magnetic field is:

The electric field of an electromagnetic wave in free space is given by $\vec{E} = 10 \cos(10^7 t + kx) \hat{j}$ V/m, where $t$ and $x$ are in seconds and meters respectively. It can be inferred that: (1) The wavelength $\lambda$ is $188.4 \text{ m}$. (2) The wave number $k$ is $0.33 \text{ rad/m}$. (3) The wave amplitude is $10 \text{ V/m}$. (4) The wave is propagating along $+x$ direction. Which one of the following pairs of statements is correct?

$\varepsilon_0$ and $\mu_0$ are the electric permittivity and magnetic permeability of free space respectively. If the corresponding quantities of a medium are $2\varepsilon_0$ and $1.5\mu_0$ respectively, the refractive index of the medium will nearly be:

To produce an instantaneous displacement current of $2 \text{ mA}$ in the space between the parallel plates of a capacitor of capacitance $4 \text{ }\mu\text{F}$, the rate of change of applied variable potential difference $\left(\frac{dV}{dt}\right)$ must be: