Find the electric field at a given point ‘O’ due to a semi-circular charged ring having linear charge density λ.
We know that the electric field due to a circular arc at a point on its Centre
E = λ2πε0rsinα2
where α is the angle subtended at the Centre. Here the angle subtended at the Centre is π
[It’s ok if you don’t remember this, I recommend you to watch the derivation video once again]
E = λ2πε0rsinπ2