Charge Q is placed at a distance r from a uniformly charged rod having 'λ' as linear charge density. The electrostatic force between them (Length of rod = L) is:

$\frac{kQλ}{(r+\frac{L}{2})}$ $\frac{kQλL}{r(r+L)}$ $\frac{kQλ}{(r+\frac{L}{2})^2}$ $\frac{kQλ}{(r^2+L^2)}$

$\frac{kQλL}{r(r+L)}$

The correct answer is Option (2) → $\frac{kQλL}{r(r+L)}$