An infinitely long wire carrying current I is along Y-axis such taht its one end is at point A(0,b) while the wire extends upto `+oo`. The magnitude of magnetic field strength at point (a,0) is

Options

A. `(mu_(0)I)/(4pia)(1+(b)/(sqrt(a^(2)+ b^(2))))`
B. `(mu_(0)I)/(4pia)(1-(b)/(sqrt(a^(2)+ b^(2))))`
C. `(mu_(0)I)/(4pia)((b)/(sqrt(a^(2)+ b^(2))))`
D. None of these

Answer

2

Explanation

B `= (mu_(0))/(4pi)(i)/(a)(sin90^(@)+sin(-theta))`
`=(mu_(0))/(4pi)(i)/(a)(1-(b)/(sqrt(a^(2)+b^(2))))`