A thin long strip whose cross-section is a semicircle carries a uniform surface charge of density s on its inner surface. Find the electric field at a point O located midway on its axis.
This is how I tried it. I considered a semicircular strip as the infinitesmial element. Then the electric field in horizontal direction gets cancelled out by symmetry. Only the downward vertical electric field remains. Then I derived a result for the electric field at a point on the axis of a uniformly charged half ring and I have used it to integrate it along the entire strip. But I get the wrong answer every time. Is this the right mathematical reasoning to do this??Can someone solve this? Thanks