Question 94: Magnetism and Matter

Question

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 :

Accepted Answer

By given information
$$32 = 4 	imes {{{\mu _0}i} \over {2r}}$$ ..... (i)
Also, $$r' = 4r$$ ...... (ii)
and $$B' = 1 	imes {{{\mu _0}i} \over {2r'}}$$ .... (iii)
$$ \Rightarrow B' = {{{\mu _0}i} \over {2(4r)}} = {{{\mu _0}i} \over {8r}} = {1 \over 8} 	imes 16 = 2\,T$$

Answer

2 T

Answer

4 T

Answer

8 T

Answer

16 T

Magnetism and Matter

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 :

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