Two point charges of magnitude 4 `mu`C and-4`mu`C are kept at points (-2 cm, 0) and (2 cm, 0) respectively. Calculate the magnitude of electric field intensity at points (0, 2 cm).

Options

A. `5.0 xx10^(-4) V//m`
B. `2.5 xx10^(-4) V//m`
C. It will depend on the orientation of the dipole
D. `1.25 xx10^(-4) V//m`

Answer

D

Explanation

For dipole –
`E prop 1/r^3, E_1/E_2 = r_2^3/r_1^3implies (1xx10^(-3))/(E_2) = ((20sqrt2)^3)/((10sqrt2)^3)`
`implies E_2=(1xx10^(-3))/8 =1.25 xx10^(-4)V//m`