The electric current in a circular coil of 2 turns produces a magnetic induction B1 at its centre. The coil is unwound and in rewound into a circular coil of 5 tuns and the same current produces a magnetic induction B2 at its centre. The ratio of ${{{B_2}} \over {{B_1}}}$ is
Solution
<p>$B = {{n{\mu _0}I} \over {2R}}$</p>
<p>${B_1} = {{2{\mu _0}I} \over {2{R_1}}}$</p>
<p>${B_2} = {{5{\mu _0}I} \over {2{R_2}}}$</p>
<p>${R_2} = {{2{R_1}} \over 5}$</p>
<p>$$ \Rightarrow {{{B_2}} \over {{B_1}}} = {5 \over 2} \times {{{R_1}} \over {{R_2}}} = {{25} \over 4}$$</p>
About this question
Subject: Physics · Chapter: Electromagnetic Induction · Topic: Self and Mutual Inductance
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