Classical Thinking

In Van de Graaff generator, potential difference is of the order of

The figure shows electric lines of force in a region. If $E_{\mathrm{A}}$ and $E_{\mathrm{B}}$ are electric fields at points $A$ and $B$ separated by distance $r$, then

The energy density of air medium is $44.25\times {10}^{-8}\mathrm{J} {\mathrm{m}}^{-3}.$ The intensity of the electric field in the medium is

($u=44.25\times {10}^{-8}\mathrm{J} {\mathrm{m}}^{-3}$, ${ϵ}_0 = 8.8541\times {10}^{-12} \mathrm{F} {\mathrm{m}}^{-1}$)

Two metal spheres of capacitance $C_{1}$ and $C_{2}$ carry some charges. They are put in contact and then separated. The final charges $Q_{1}$ and $Q_{2}$ on them will satisfy

The potentials of two plates of a capacitor are $+10 \mathrm{V}$ and $-10 \mathrm{V}$. The charge on one of the plates is $40 \mathrm{C}$. The capacitance of the capacitor is

A $100 \mathrm{\mu F}$ capacitor is to have an energy content of $50 \mathrm{J}$ in order to operate a flashlamp. The voltage required to charge the capacitor is

The capacitance between the points $P$ and $Q$ in the following circuit, is

Four capacitors are connected as shown in the figure. The equivalent capacitance between $A$ and is $B$