- #1
Buffu
- 849
- 146
Homework Statement
Consider a high voltage direct power line which consist of two conductor suspended 3 meters apart. The lines are oppositely charged, If electric field halfway between them is ##15000N/C## how much is the excess positive charge on a 1 km length of positive conductor ?
Homework Equations
##\displaystyle E = {2Q \over y \sqrt{4y^2 + l^2}}##
where ##l## is length of wire, ##y## is the distance of the charge from the wire and the wire is kept on the x-axis.
The Attempt at a Solution
Electric field between the conductors will be sum of indiviual E fields, so I calculated indiviual E field and then took the sum.
##\displaystyle E_{+ve} = {4kQ \over 3 \sqrt{9 + 10^6}}##
##\displaystyle E_{-ve} {-4kq \over 3\sqrt{9 + 10^6}}##
Solve for ##Q - q## in ##E = E_{+ve} + E_{-ve}## I get ##1.25 \times 10^{-3} C##
But the given answer is ##6.26 \times 10^{-4} C##
Am I missing something ?