List of top Physics Questions on Electrostatics asked in NEST

A laser beam of wavelength $1\text{ }\mu\text{m}$ is split and sent into two vacuum cavities of equal length $L$ as shown in the figure. A detector can register an interference signal only if the phase difference between the returning beams is at least $5 \times 10^{-11}\text{ rad}$. A certain physical effect changes the length of cavity 2 by an amount $\Delta L$ such that $\Delta L / L \approx 10^{-21}$. The minimum cavity length (in km) needed for measuring this physical effect is approximately

A parallel plate capacitor with circular plates of radius $R$ is being charged as shown in the figure. Let $B(r)$ be the induced magnetic field at a distance $r$ from the central axis between the plates. Assuming $d \ll R$, the ratio $\frac{B(2d)}{B(d)}$, while charging, is

All the capacitors in a given circuit are initially fully charged with all switches open. At a later time $t$, all the switches are simultaneously closed. The current flowing through the circuit at that instant is given by

An infinitely long straight wire with uniform line charge density $\lambda$ lies at a perpendicular distance $d$ from a point O. The total electric flux through the surface of a sphere of radius $R \gt d$ centred at O, is

An electromagnetic wave travels from vacuum into a non-magnetic dielectric medium with permittivity $\epsilon = 4\epsilon_0$. If the ratio ($E_0 / B_0$) of the electric field amplitude $E_0$ to the magnetic field amplitude $B_0$ in vacuum is equal to the speed of light $c$, then the corresponding ratio in the given medium is

Among the following, the waves responsible for energy transfer in vacuum are

Three positive and two negative charges each of magnitude \(q\) are placed at five of the six vertices of a regular hexagon of side \(R\). The work done to bring a negative charge \(-q\) from infinity to the centre of the hexagon is: