A circular segment of radius `20cm` subtends an angle of `60^@` at its centre. Figure A current of `10A` is flowing through it. Find the magnitude and direction of the magnetic field produced at the centre.

Answer

`5*2xx10^-6T`

Explanation

Let `hatn` be a unit vector perpendicular to the plane of paper upwards. Then total magnetic field at O due to current through the given structur is
`vecB=vecB_(ab)+vecB_(bc)+vecB_(cd)=0+(mu_0)/(4pi)I/rtheta(-hatn)+0`
[As point O lies on the wire ab and cd, so `B_(ab)=0=B_(cd)`]
`:. B=(mu_0)/(4pi)I/rtheta=10^-7xx(10)/((20xx10^-2))xxpi/3`
`=5*2xx10^-6T`