The electric field in a region is given by E =( A x+ B ) i, where E is in NC^-1 and x is in metres. The values of constants are A =20 SI unit and B…

The electric field in a region is given by $\displaystyle \overrightarrow{\mathrm{E}}=(\mathrm{A} x+\mathrm{B}) \hat{i}$, where E is in $\displaystyle \mathrm{NC}^{-1}$ and $\displaystyle x$ is in metres. The values of constants are $\displaystyle \mathrm{A}=20$ SI unit and $\displaystyle \mathrm{B}=10$ SI unit. If the potential at $\displaystyle x=1$ is $\displaystyle \mathrm{V}_1$ and that at $\displaystyle x=-5$ is $\displaystyle \mathrm{V}_2$, then $\displaystyle \mathrm{V}_1-\mathrm{V}_2$ is :