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The magnetic field at a distance r from ...

The magnetic field at a distance r from a long wire carryimg current I is 0.4 T. The magnetic field at a distance 2r is

A

0.2 tesla

B

0.8 tesla

C

0.1 tesla

D

1.6 tesla

Text Solution

Verified by Experts

The correct Answer is:
A
`B = (mu_0i)/(2pir) " or " B prop 1/ r`
When r is double , the magnetic field becomes half, i.e., now the magnetic field will be 0.2 T .
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