Two very large thin conducting plates having same cross sectional area are placed as shown in figure. They are carrying charges `Q` and `3Q`, respectively. The variation of electric field as a function at x (for `x=0` to `x=3d`) will be best represented by

Options

A.
B.
C.
D.

Answer

C

Explanation

`E_1=sigma/(2epsilon_0)+(3sigma)/(2epsilon_0)=(2sigma)/epsilon_0=E_3`
`E_2=(3sigma)/(2epsilon_0)-sigma/(2epsilon_0)=sigma/epsilon_0`
`E_1 and E_2` are in the negative direction and `E_3` in positive direction.