A) B/6
B) B/3
C) B/4
D) B/2
Correct Answer: B
Solution :
(b) B/3 In a long straight wire, \[B=\frac{{{\mu }_{0}}l}{2\pi r}\Rightarrow B\propto \frac{1}{r}\] \[\therefore \frac{B}{{{B}_{1}}}=\frac{{{r}_{2}}}{{{r}_{1}}}\Rightarrow \frac{B}{{{B}_{1}}}=\frac{12}{4}=3\] \[\Rightarrow B=3{{B}_{1}}\] or \[{{B}_{1}}=B/3\].You need to login to perform this action.
You will be redirected in
3 sec