A point charge q is kept at a distance r from an infinitely long straight wire with charge density λ. The magnitude of the electrostatic force…

A point charge $\displaystyle \mathrm{q}$ is kept at a distance $\displaystyle \mathrm{r}$ from an infinitely long straight wire with charge density $\displaystyle \lambda$. The magnitude of the electrostatic force experienced by charge $\displaystyle \mathrm{q}$ is :