The electric intensity due to a dipole of length `10 cm` and having a charge of `500 muC`, at a point on the axis at a distance `20 cm` from one of the charges in air is

Options

A. `6.25 xx10^(7) N//C`
B. `9.28 xx10^(7) N//C`
C. `13.1 xx10^(11) N//C`
D. `20.5 xx10^(7) N//C`

Answer

A

Explanation

`2a = 0.1 m, q = 500 muC , r = 0.25 cm`
Since, r is comparable of a
`E=(K(2p)r)/((r^2-a^2)^2)=(9xx10^9 xx2 xx(2aq) xx0.25)/([(0.25 )^2 -(0.05)^2]^2)`
`= (9xx10^9 xx2xx0.1 xx5 xx10^(-4)xx0.25)/([(0.25 )^2 - (0.05)^2]^(2))`
`= 6.25 xx10^7 N//C`