For a $GPS$ navigation to track a mobile device,we use :-

$A$ laser beam is operating at $100 \,mW$. The amount of energy stored by $90 \,cm$ length of this laser beam will be

For an $EM$ wave,the electric and magnetic fields are $300 \ V m^{-1}$ and $7.9 \ A m^{-1}$ respectively. The maximum rate of energy flow is, (in $W m^{-2}$)

$A$ physical quantity $\vec{S}$ is defined as $\vec{S}=(\vec{E} \times \vec{B}) / \mu_0$,where $\vec{E}$ is the electric field,$\vec{B}$ is the magnetic field,and $\mu_0$ is the permeability of free space. The dimensions of $\vec{S}$ are the same as the dimensions of which of the following quantity(ies)?
$(A)$ $\frac{\text{Energy}}{\text{charge} \times \text{current}}$
$(B)$ $\frac{\text{Force}}{\text{Length} \times \text{Time}}$
$(C)$ $\frac{\text{Energy}}{\text{Volume}}$
$(D)$ $\frac{\text{Power}}{\text{Area}}$

Which of the following is a wrongly matched pair?

$A$ parallel plate capacitor has a capacitance $C = 200 \ pF$. It is connected to a $230 \ V$ $AC$ supply with an angular frequency $\omega = 300 \ rad/s$. The $rms$ value of the conduction current in the circuit and the displacement current in the capacitor,respectively,are: