The electrical potential function for an electrical field directed parallel to the x-axis is shown in the given graph.
Draw the graph of electric field strength.

Options

A. `-2 le x le 0, 4 le x le 8`, and `0 le x le 2`
B. `-2 le x le 0` and `0 le x le 2`
C. `-2 le x le 0, 2 le x le 4`, and `le x le 8`
D. `0 le x le 2` and `4 le x le 8`

Answer

C

Explanation

`E_(r)=-(DeltaV)/(Deltar), E_(x)=-(DeltaV)/(Deltax)`
For `-2 le x le 0, E_(x)=-((10-0))/([0-(-2)])=-5 NC^(-1)`
For `0 le x le 2, E_(x)=0`
For `2 le x le 4, E_(x)=-([20-10])/([4-2])=-5 NC^(-1)`
For `4 le x le 8, E_(x)=-([0-20])/([8-4])=5 NC^(-1)`