PQ is a current - carrying long straight conductor in the plance of the paper as shown in the following figure. A and B are two points at distances `r_(1)` and `r_(2)` from it .

If `r_(2) gt r_(2)` at which point will the strength of the magnetic field be greater ? Justify your answer .

Explanation

The magnetic field at a point near the current - carrying straight conductor is `B prop (1)/(r) `.
Hence , at point A `B_(1) prop (1)/(r_(1))` and at point B `B_(2) prop (1)/(r_(2))`
As `r_(1) lt r_(2) , B_(1) gt B_(2)` .