Physics · PYQ NEET UG 2019(1)
हिन्दीTwo parallel infinite line charges with linear charge densities \( +\lambda\text{ C/m} \) and \( -\lambda\text{ C/m} \) are placed at a distance of \( 2R \) in free space. What is the electric field mid-way between the two line charges?
Correct answer · Option 1
\( \frac{\lambda}{\pi\varepsilon_0 R}\text{ N/C} \)
Explanation
Electric field due to a line charge is \( E = \frac{\lambda}{2\pi\varepsilon_0 r} \). At the mid-point, fields due to both charges point in the same direction and add up to \( E = \frac{\lambda}{2\pi\varepsilon_0 R} + \frac{\lambda}{2\pi\varepsilon_0 R} = \frac{\lambda}{\pi\varepsilon_0 R} \).