If i= 2A and R=0.4 m, find the magnetic flux density at O.

Explanation

Magnetic flux density at O due to ABC is
`B_(ABC) =(mu_(0)i)/(4(R )) =((4pi xx 10^(-7)) xx 2)/(4xx(0.4))`
`=1.57 xx 10^(-6)T`
(Directed upward to the plane of paper)
Magnetic flux density at O due to PDQ is
`B_(PDQ)=(mu_(0)i)/(4((R )/(2)))`
`=((4pi xx 10^(-7))xx2)/(4xx((0.4)/(2)))`
`=3.14 xx 10^(-6)T`
(Directed upward to the plane of paper)
Magnetic flux density due to AP and QC at O will be zero.
So, `B_("net")=B("ABC")= B_("PDQ")`
`=(1.57 xx 10^(-6)) +(3.14 xx 16^(-6))`
`=4.71 xx 10^(-6)T`
which is net magnetic flux density at O.