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Magnetic Effects & Magnetism

JEE Main level, single correct, medium

100 of 276

Question 100 of 276

A long solenoid has 200 turns per $\mathrm{cm}$ and carries a current $\mathrm{i}$ . The magnetic field at its centre is $6.28 \times 10^{-2}$ Weber $/ \mathrm{m}^2$ . Another long solenoid has 100 turns per $\mathrm{cm}$ and it carries a current $\mathrm{i} / 3$ . The value of the magnetic field at its centre is

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Answer: (B) $1.05 \times 10^{-2}$ Weber $/ \mathrm{m}^2$

B_2=\frac{B_1 n_2 i_2}{n_1 i_1}=\frac{\left(6.28 \times 10^{-2}\right)(100 \times i / 3)}{200(i)}=1.05 \times 10^{-2} \mathrm{~W} / \mathrm{m}^2

JEE Main question paper PDF

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JEE Main 2025 Apr 2 Shift 1 question paper

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