Refractive index of a medium is $\mu$. If the angle of incidence is twice that of the angle of refracation, then the angle of incidence is

Two slits are made one millimetre apart and the screen is placed one metre away from the slits. The fringe width when light of wavelength 500 nm is used is

The flux of the electric field $\mathbf{E}=24 \hat{\mathbf{i}}+30 \hat{\mathbf{j}}+28 \hat{\mathbf{k}} \mathrm{NC}^{-1}$ through an area of $20 \mathrm{~m}^2$ on the $Y Z$-plane is

The effective capacitance between points $A$ and $B$ shown in the figure is