An element l = x i is placed at the origin and carries a large current I = 10 A. The magnetic field on the y-axis at a distance of 0.5 m from the element x of 1 cm length is: [figure]
- 10 10-8 T
- 8 10-8 T
- 4 10-8 T
- 12 10-8 T
Answer
(3) 4 10-8 T
Solution
Biot–Savart law: B = 04 I l r2
l is along x and r is along y = 90
B = 10-7 10 (1 10-2) 1(0.5)2
= 4 10-8 T
Answer: (3)