Question

The magnetic field at a distance r from a long wire carrying current i is 0.4 Tesla. The magnetic field at a distance 2r is

• A. 0.2 Tesla
• B. 0.8 Tesla
• C. 0.1 Tesla
• D. 1.6 Tesla

Answer 1

Answer: (A)

0.2 Tesla

Answer 2

$r$ is doubled, is halved.