OnlineCBT
Physics · JEE | Moving Charges and Magnetism
हिन्दीA long straight wire carries a current \( I \). At what distance from the wire is the magnitude of magnetic field equal to one-fourth of the field at a distance \( d \) from the wire?
View Answer & Solution
Correct answer · Option A
\( 4d \)
Explanation
Since magnetic field \( B \propto \frac{1}{r} \), reducing field to \( \frac{1}{4} \) requires increasing distance by a factor of 4, i.e., \( 4d \).
