The plates of small size of a parallel plate capacitor are charged as shown. The force on the charged particle of 'q' at a distance 'l' from the capacitor is : (Assume that the distance between the plates is `d ltlt l`)

Options

A. zero
B. `(Qqd)/(2 pi epsilon_(0)l^(3))`
C. `(Qqd)/(pi epsilon_(0)l^(3))`
D. `(Qqd)/(4 piepsilon_(0)l^(3))`

Answer

B

Explanation

The two plates acts as a dipole

`therefore` Force on charge q:
`F=Eq=((2 kQd)/(l^(3)))q=(Qqd)/(2piepsilon_(0)l^(3))`