NEET-XII-Physics
38: Electromagnetic Induction
- #5A conducting circular loop of area 1 mm2 is placed coplanarly with a long, straight wire at a distance of 20 cm from it. The straight wire carries an electric current which changes from 10 A to zero in 0.1 s. Find the average emf induced in the loop in 0.1 s.Ans : Given:
Area of the loop, A = 1 mm2
Current through the wire, i = 10 A
Separation between the wire and the loop, d = 20 cm
Time, dt = 0.1 s
The average emf induced in the loop is given by
`` e=\frac{\,\mathrm{\,d\varphi \,}}{\,\mathrm{\,d\,}t}``
`` =\frac{BA}{\,\mathrm{\,d\,}t}=\frac{{\mu }_{0}i}{2\pi d}\times \frac{A}{\,\mathrm{\,d\,}t}``
`` =\frac{4\,\mathrm{\,\pi \,}\times {10}^{-7}\times 10}{2\,\mathrm{\,\pi \,}\times 2\times {10}^{-1}}\times \frac{{10}^{-6}}{1\times {10}^{-1}}``
`` =1\times {10}^{-10}\,\mathrm{\,V\,}``
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