Electromagnetism - Physics Previous Year Questions

A silver wire of radius \(0.1 \mathrm{~cm}\) carries a current of \(2 \mathrm{~A}\). If the charge density in silver is \(5.86 \times 10^{28} \mathrm{~m}^{-3}\), the drift velocity is

A capacitor is filled with two dielectrics of the same dimensions but of dielectric constants 2 and 3 as shown in Fig.(a) and then in Fig.(b). Then ratio of the capacitor in the two arrangements is

Susceptibility of ferromagnetic substance is

Eight dipoles of charges of magnitude $e$ each are placed inside a cube. The total electric flux coming out of the cube will be

The temperature coefficient of the resistance of a wire is 0.00125 per \({ }^{\circ} \mathrm{C}\). At \(300 \mathrm{~K}\) its resistance is \(1 \Omega\). The resistance of wire will be \(2 \Omega\) at

A parallel plate capacitor with plate area \(A\) and separation between the plates \(d\) is charged by a constant current \(i\). Consider a plane surface of area \(A / 2\) parallel to the plates and drawn simultaneously between the plates. The displacement current through this area is