Answer:
[tex]F = \frac{Qq}{2\pi \epsilon_0 L d}[/tex]
Explanation:
As we know that if a charge q is distributed uniformly on the line then its linear charge density is given by
[tex]\lambda = \frac{q}{L}[/tex]
now the electric field due to long line charge at a distance d from it is given as
[tex]E = \frac{2k\lambda}{d}[/tex]
[tex]E = \frac{q}{2\pi \epsilon_0 d}[/tex]
now the force on the other charge in this electric field is given as
[tex]F = QE[/tex]
[tex]F = \frac{Qq}{2\pi \epsilon_0 L d}[/tex]