Answer & explanation
Correct answer: option 2
magnetic Field is $B = \frac{\mu_0 I}{2r} = \frac{\mu_0 q}{2rT}$
Since $ r \propto n^2 , T \propto n^3 , rT \propto n^5$
$ \Rightarrow B \propto n^{-5}$
Correct answer: option 2
magnetic Field is $B = \frac{\mu_0 I}{2r} = \frac{\mu_0 q}{2rT}$
Since $ r \propto n^2 , T \propto n^3 , rT \propto n^5$
$ \Rightarrow B \propto n^{-5}$