Question

Two charges of +25 × 10–9 coulomb and –25 × 10–9 coulomb are placed 6 m apart. find the electric field intensity ratio at points 4 m from the centre of the electric dipole (i) on axial line (ii) on equatorial line

Answer 1

P=q(2r)

 =25 x $10^{-9}$ x 6

P=1.5 x $10^{-7}$

$E_{axial}$=k.2Pr/[$r^{2}$-$a^{2}$]^2

=9 x $10^{9}$ x 2 x 1.5 x $10^{-7}$ x 4/[$4^{2}$-$3^{2}$]2

$E_{axial}$=10800/49

$E_{equi}$=k.P/[$r^{2}$+$a^{2}$]^3/2

=9 x $10^{9}$ x 1.5 x $10^{-7}$/[$4^{2}$+$3^{2}$]^3/2

=1350/125

$E_{axial}$/$E_{equi}$=1000/49

Answer 2

answer: 1000/49 use axial formula and equotorial formula