For a plane electromagnetic wave propagating in the \(x\)-direction, which one of the following combinations gives the correct possible directions for the electric field \((E)\) and magnetic field \((B)\) respectively?
1. \(\hat{j}+\hat{k},~-\hat{j}-\hat{k}\)
2. \(-\hat{j}+\hat{k},~-\hat{j}+\hat{k}\)
3. \(\hat{j}+\hat{k},~\hat{j}+\hat{k}\)
4. \(-\hat{j}+\hat{k},~-\hat{j}-\hat{k}\)

A capacitor of capacitance \(C\) is connected across an AC source of voltage \(V\), given by;
\(V=V_0 \sin \omega t\)$\mathrm{}$
The displacement current between the plates of the capacitor would then be given by:
1. \( I_d=\frac{V_0}{\omega C} \sin \omega t \)
2. \( I_d=V_0 \omega C \sin \omega t \)
3. \( I_d=V_0 \omega C \cos \omega t \)
4. \( I_d=\frac{V_0}{\omega C} \cos \omega t\)

Assume a bulb of efficiency \(2.5\%\) as a point source. The peak values of the electric field and magnetic field produced by the radiation coming from a \(100~\text{W}\) bulb at a distance of \(3~\text{m}\) are respectively:

Light with an energy flux of \(18~\text{W/cm}^{2}\) falls on a non-reflecting surface at normal incidence. If the surface has an area of \(20~\text{cm}^{2}\), what is the average force exerted on the surface during a \(30\) minute time span?
1. \(2.1\times10^{-6}~\text{N}\)
2. \(1.8\times10^{-6}~\text{N}\)
3. \(1.2\times10^{-6}~\text{N}\)
4. \(2.1\times10^{-5}~\text{N}\)$\mathrm{}$

The magnetic field in a plane electromagnetic wave is given by;
\(B_y=\left(2 \times 10^{-7}\right) \sin \left(0.5 \times 10^3 {x}+1.5 \times 10^{11} {t}\right)~\text{T}\).
The expression for the electric field is:

The magnetic field in a plane electromagnetic wave is given by \(\mathrm{B}=\left(2 \times 10^{-7}\right) \mathrm{T} \sin \left(0.5 \times 10^3 \mathrm{x}+1.5 \times 10^{11} \mathrm{t}\right )\). The wavelength and frequency of the wave are respectively:

A plane electromagnetic wave of frequency 25 MHz travels in free space along the x-direction. At a particular point in space and time, $$\(\vec{E_{0}}=6.3~ \hat{j}~V/m\). What is \(\vec{B_{0}}\) at this point?
1. \(2.1\times 10^{-8} \hat{k}~\text{T}\)
2. \(1.2\times10^{-8} \hat{k}~\text{T}\)
3. \(2.1\times10^{-8} \hat{j}~\text{T}\)
4. \(1.2\times10^{-8} \hat{j}~\text{T}\)$\mathrm{}$

A parallel plate capacitor with circular plates of radius 1 m has a capacitance of 1 nF. At t = 0, it is connected for charging in series with a resistor R = 1 M$\Omega$ across a 2V battery (as shown in the figure). Find the magnetic field at a point P, halfway between the centre and the periphery of the plates, after t = 10^–3 s. (The charge on the capacitor at time t is q (t) = CV[1 – exp (–t/$\tau$)], where the time constant $\tau$ is equal to CR.) 

$1. 0.74\times {10}^{-13} T$
$2. 0.67\times {10}^{-13} T$
$3. 0.74\times {10}^{-12} T$
$4. 0.67\times {10}^{-12} T$

The magnetic field in a plane electromagnetic wave is given by:
\(B_y = 2\times10^{-7} \text{sin}\left(\pi \times10^{3}x+3\pi\times10^{11}t\right )T\)${}_{}$
The wavelength is:
1. \(\pi\times 10^{3}~\text{m}\)
2. \(2\times10^{-3}~\text{m}\)
3. \(2\times10^{3}~\text{m}\)
4. \(\pi\times 10^{-3}~\text{m}\)

The EM wave with the shortest wavelength among the following is: