Variation of electrostatic potential along the $x$-direction is shown is figure. The correct statement about electric field is

In moving from $A$ to $B$ along an electric field line, the work done by electric field on an electron is $6.4\times {10}^{-19} \mathrm{J}.$If ${\mathrm{\varphi }}_1 \mathrm{and} {\mathrm{\varphi }}_2$ are equipotential surfaces, then the potential difference $V_C - V_A$ is 

An electron is taken from point $A$ to point $B$ along the path $AB$ in a uniform electric field of intensity $E = 10 \mathrm{V} {\mathrm{m}}^{-1}$. Side $AB = 5 \mathrm{m}$ and side $BC= 3 \mathrm{m}$. Then the amount of work done on the electron by us is

The variation of potential with distance $R$ from the fixed point is shown in figure. The electric field at $R=5 \mathrm{m}$ is,

Figure shows two equipotential lines in the $xy$ plane for an electric field. The scales are marked. The $x$-component and $y$-component of the field in the space between these equipotential lines are, respectively,