The electric current in a circular coil of four turns produces a magnetic induction 32 T at its centre. The coil is unwound and is rewound into a circular coil of single turn, the magnetic induction at the centre of the coil by the same current will be :
Solution
<p>By given information</p>
<p>$32 = 4 \times {{{\mu _0}i} \over {2r}}$ ..... (i)</p>
<p>Also, $r' = 4r$ ...... (ii)</p>
<p>and $B' = 1 \times {{{\mu _0}i} \over {2r'}}$ .... (iii)</p>
<p>$$ \Rightarrow B' = {{{\mu _0}i} \over {2(4r)}} = {{{\mu _0}i} \over {8r}} = {1 \over 8} \times 16 = 2\,T$$</p>
About this question
Subject: Physics · Chapter: Magnetic Effects of Current · Topic: Biot-Savart Law
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