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The dipole moment of a circular loop carrying a current I , is m and the magnetic field at the centre of the loop is B 1 . When the dipole moment is doubled by keeping the current constant, the magnetic field at the centre of the loop is B 2 . The ratio 2 1 B B is :

1. 2
2. 3
3. 2
4. 2 1 Students may find similar question in CP exercise sheet : [ JEE Main, Chapter : Magnetic Effect of Current ]

Correct answer: 2

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