Let `B_(P)` and `B_(Q)` be the magnetic field produced by the wire P and Q which are placed symmetrically in a rectangular loop ABCD as shown in figure. Current in wire P is I directed inward and in Q is 2I directed outwards.

If `int_(A)^(B)vecB_(Q).vecdl=wmu_(0) "tesla meter",int_(D)^(B)vecB_(P).vecdl=-2mu_(0)` tesla meter
`&` int_(A)^(B)vecB_(P)vecdl=-mu_(0)` tesla meter
the value of 1 will be:

Options

A. 8A
B. 4A
C. 5A
D. 6A

Answer

D

Explanation

`(2mu_(0)-mu_(0))+(-mu_(0)+2mu_(0))+(-2mu_(0)+4mu_(0))+(4mu_(0)-2mu_(0))=mu_(0)IrArrI=6A`