Question

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
A. `6.25 xx 10^(7) N//C`
B. `9.28 xx 19^(7) N//C`
C. `13.1 xx 11^(11) N//C`
D. `20.5 xx 10^(7) N//C`

Answer 1

Correct Answer - a
By using `E= 9xx10^(9).(2pr)/((r^(2)-l^(2))^(2)`

Where `p= (500xx10^(-6))xx(10xx10^(-2))= 5xx10^(-5) cxxm`,
`r= 25 cm= 0.25, l= 5 cm= 0.05m`
`E=(9xx10^(9)xx2xx5xx10^(-5)xx0.25)/({(0.25)^(2)-(0.05)^(2)}^(2))`
`= 6.25xx10^(7) N//C`