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Question
A current of 10 A is established in a long wire along the positive z-axis. Find the magnetic field \[\vec{B}\] at the point (1 m, 0, 0).
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Solution
Given:
Magnitude of current, I = 10 A
Separation of the point from the wire, d = 1 m

The magnetic field \[\vec{B}\] at point (1 m, 0, 0) is given by
\[B = \frac{\mu_0 i}{2\pi d} = \frac{4\pi \times {10}^{- 7} \times 10}{2\pi \times 1}\]
\[ \Rightarrow B = 2 \times {10}^{- 6} T\]
(Along the +ve y-axis by the right-hand thumb rule)
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