A wire, of length L(=20 cm), is bent into a semi-circular arc. If the two equal halves, of the arc, were each to be uniformly charged with charges Coulomb where is the permittivity (in SI units) of free space] the net electric field at the centre O of the semi-circular arc would be :
As we learnt in
Linear charge distribution -
charge per unit length.
wire, circulating ring ex.
So due to each quarter section field intensity