A) \[6\times {{10}^{-7}}N\text{ }{{m}^{-1}}\text{ }attractive\]
B) \[6\times {{10}^{-5}}\text{ }N\text{ }{{m}^{-1}}\text{ }attractive\]
C) \[6\times {{10}^{-7}}\text{ }N\text{ }{{m}^{-1}}\text{ }repulsive\]
D) \[6\times {{10}^{-5}}\text{ }N\text{ }{{m}^{-1}}\text{ }repulsive\]
Correct Answer: C
Solution :
: The force per unit length acting between two parallel wires carrying currents \[{{I}_{1}}\] and \[{{I}_{2}}\]and placed a distance d apart is \[f=\frac{{{\mu }_{0}}{{I}_{1}}{{I}_{2}}}{2\pi d}\] Here, \[{{I}_{1}}=1A,\,{{I}_{2}}=3A,\,\,d=1m\] \[{{\mu }_{0}}=4\pi \times {{10}^{-7}}Tm\,{{A}^{-1}}\] \[\therefore \] \[f=\frac{(4\pi \times {{10}^{-7}}T\,m\,{{A}^{-1}})(1A)(3A)}{2\pi (1m)}\] \[=6\times {{10}^{-7}}\,N\,{{m}^{-1}}\] As the currents are in opposite directions, so f is repulsive.You need to login to perform this action.
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