Question

Zero gauge wire has a diameter of 0.32in and can carry a sustained current of 150A safely. What is the magnetic field a distance 5cm from the center of a long straight segment of zero gauge wire carrying a current of 150A? This would be the field experienced by a bird sitting on the wire. Select One of the Following:
(a) 1.2 × 10−2T
(b) 1.9 × 10−3T
(c) 3.0 × 10−4T
(d) 6.0 × 10−4T
(e) 1.0 × 10−6T

Answer 1

Answer: d) 6*10^-4 T

Explanation: In order to explain this problem we have to use the Ampere law to calculate the magnetic field, which is given by:

∫B*dl=μo*I  then

B=μo*I/(2*π*r)  where r and I are the distance to the wire and the current in the wire. μo is equal 4*π*10^-7 Wb/A*m

Finally, we have:

B=4*π*10^-7*150/(2*π*0.05)=6*10^-4 T