Physics

Problem

A very long straight rod starts at point O and extends infinitely in the positive

x

-direction. The rod carries a uniform linear charge density

\lambda

. A point charge

q

is fixed on the

x

-axis at a distance

a

to the left of O. Which expression gives the magnitude of the force on the point charge? a)

\displaystyle \frac{2kq\lambda}{a}

\displaystyle \frac{kq\lambda}{a}

\displaystyle \frac{kq\lambda\ln 2}{a}

\displaystyle \frac{kq\lambda}{2a}