Question

The electric potential decreases uniformly from $120V$ to $80V$ as one move on the x-axis from $x=-1cm$ to $x=+1cm$. The electric field at the origin?

Answer 1

Step 1: Given data

Electric potential decreases from $120V$ to $80V$

On the x-axis from $x=-1cm$ to $x=+1cm$

Step 2: Calculation

Formula for electric firld, $E=-\frac{dV}{dr}$, where $V$ is electric potential and $r$ is length.

⇒$E=-\frac{80-120}{1-(-1)}$

⇒$E=20V/cm$

⇒ The electric field at the origin is $E=20V/cm$.