Complete question:
A long, straight wire lies along the z-axis and carries a 4.00-A current in the +z-direction. Find the magnetic field (magnitude and direction) produced at the following points by a 0.500-mm segment of the wire centered at the origin:
(a) x = 2.00 m, y = 0, z = 0;
(b) x = 0, y = 2.00 m, z = 0;
(c) x = 2.00 m, y = 2.00 m, z = 0; (d) x = 0, y = 0, z = 2.00 m.
Answer:
a) ;
b) ;
c) ;
d) 0
Explanation:
Given
I = 4.20A
P = 0.500mm
a) r= (2.00m) i
∆;
;
b) r = (2.00m) j
∆;
;
c) r = (2.00m) (i+j)
;
∆;
;
d) r = (2.00m) k
∆;
B = 0