Figure shows the electric lines of force emerging from a charged body. If the electric field at $A$ and $B$ are ${E_A}$ and ${E_B}$ respectively and if the displacement between $A$ and $B$ is $r$ then
${E_A} > {E_B}$
${E_A} < {E_B}$
${E_A} = \frac{{{E_B}}}{r}$
${E_A} = \frac{{{E_B}}}{{{r^2}}}$
A point charge $+10\; \mu \,C$ is a distance $5 cm$ directly above the centre of a square of side $10 \;cm ,$ as shown in Figure. What is the magnitude of the electric flux through the square?
Figure shows the electric field lines around three point charges $A, \,B$ and $C$.
$(a)$ Which charges are positive ?
$(b)$ Which charge has the largest magnitude ? Why ?
$(c)$ In which region or regions of the picture could the electric field be zero ? Justify your answer.
$(i)$ Near $A$ $(ii)$ Near $B$ $(iii)$ Near $C$ $(iv)$ Nowhere
Discuss some points about Gauss’s law.
Using thomson's model of the atom, consider an atom consisting of two electrons, each of charge $-e$, embeded in a sphere of charge $+2e$ and radius $R$. In equilibrium each electron is at a distance $d$ from the centre of the atom. What is the equilibrium separation between electrons
Three positive charges of equal value $q$ are placed at the vertices of an equilateral triangle. The resulting lines of force should be sketched as in