Three infinitely long charge sheets are placed as shown in figure. The electric field at point `P` is

Options

A. `(2 sigma)/epsilon_(0) hat(k)`
B. `-(2 sigma)/epsilon_(0) hat(k)`
C. `(4 sigma)/epsilon_(0) hat(k)`
D. `-(4 sigma)/epsilon_(0) hat(k)`

Answer

B

Explanation

All the three plates will produce electric field at P along negative z-axis. Hence,
`vec(E)_(p)=[sigma/(2epsilon_(0))+(2sigma)/(2epsilon_(0))+sigma/(2epsilon_(0))](-hat(k))=-(2sigma)/epsilon_(0)hat(k)`