Answer:
(a) B = 5.6 micro Tesla
Explanation:
Current in the wire, i = 140 A
distance, r = 5 m
The formula for the magnetic field at a distance r due to the current carrying wire
[tex]B=\frac{\mu _{0}}{4\pi }\times \frac{2i}{r}[/tex]
[tex]B=10^{-7}\times \frac{2\times140}{5}[/tex]
B = 5.6 x 10^-6 Tesla
B = 5.6 micro Tesla
(b) As the magnetic field of earth at this site is 20 micro tesla so the magnetic field due to current carrying wire interfere the magnetic compass.
