AP EAPCET 23-Aug-2021 Shift 1 Paper

Given, charge of dipole, q=500×10−6C
Separation between charges, 2a=10‌cm =10×10−2m
Distance of location from mid point of axis, r=25‌cm=25×10−2m
∵ Electric field on axis of dipole, E=

4kqar

(r2−a2)2

where, k is Coulomb's constant =9×109C2m−2N−1 =

2.25×105

[0.0625−0.0025]2

=

2.25×105

(0.06)2

=

2.25×105

36×10−3

=6.25×107 ≈6×107NC−1
The result is close to option (a).