Electromagnetic Induction

JEE Main level, single correct, medium

2 of 153

Question 2 of 153

A circular coil of radius R=10 cmR=10\,\text{cm} and 500500 turns carries current 1 A1\,\text{A}. The magnetic field at its centre is (BB in mT\text{mT}):

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Answer: (D) π\pi

B=μ0NI2R=4π×10−7×500×12×0.1=π×10−3 T=π mTB = \frac{\mu_0 N I}{2R} = \frac{4\pi \times 10^{-7} \times 500 \times 1}{2 \times 0.1} = \pi \times 10^{-3}\,\text{T} = \pi\,\text{mT}.

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