A) B/2
B) 2 B
C) B
D) 4 B
Correct Answer: B
Solution :
When two parallel conductors carry currents \[\text{I}\] and \[2I\]in the same direction, then magnetic field at the mid-point is \[B=\frac{{{\mu }_{0}}2I}{2\pi r}-\frac{{{\mu }_{0}}I}{2\pi r}=\frac{{{\mu }_{0}}I}{2\pi r}\] When current \[2I\]is switched off then magnetic field due to conductor carrying current \[I\]is \[B=\frac{{{\mu }_{0}}I}{2\pi r}.\]Hence, option (c) is correct.You need to login to perform this action.
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