A current `I ` flows radius along a lengthy thin-walled tube of radisu `R` with longiitual slit of width `h`. Find the induction of the magnietic field inside the tube under the condition `h lt lt R`

Explanation

The thin walled tube with a longitudinal slit can be considered equivalent to a fill tube and a strip carrying the same current density in the opposite direction. Inside the tube, the former does not contibute so the total magnetic field is simply that due to the strip. It is
`B = (mu_(0))/(2pi) ((I//2 pi R) h)/(r) = (mu_(0) I h)/(4 pi^(2) R r)`
where `r` is the distance of the find point from the strip.