At what distance r from the suspended wire, the new wire (having the same current) should be placed to keep it stationary.
A) 2.9 m
B) 1.9 m
C) 1.3 m
D) 2.4 m
Correct Answer: C
Solution :
Torque about O due to the new wire will be \[\lambda =\left( \frac{{{\mu }_{0}}i}{2\pi r} \right)(L)(i).\frac{L}{2}\] \[\left( \frac{{{\mu }_{0}}}{2\pi } \right)\frac{{{i}^{2}}{{L}^{2}}}{2r}\] Equating this With \[{{\tau }_{0}}\] of Eq. (i), we get \[\frac{L}{2r}=0.386\] \[\therefore \] \[r=\frac{L}{2\times 0.386}=\frac{1}{2\times 0.386}=1.3m\]
You need to login to perform this action.
You will be redirected in
3 sec
