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Question
A copper wire of diameter 1.6 mm carries a current of 20 A. Find the maximum magnitude of the magnetic field `vecB` due to this current.
Solution
Given:
Magnitude of current, I = 20 A
Diameter of the wire, d = 1.6 × 10−3 m
∴ Radius of the wire = 0.8 × 10−3 m
The magnetic field intensity is given by
\[B = \frac{\mu_0 I}{2\pi r}\]
\[= \frac{2 \times {10}^{- 7} \times 20}{0 . 8 \times {10}^{- 3}} = 5\] mT
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