Question 293: Magnetism and Matter

Question

A closely wounded circular coil of radius 5 cm produces a magnetic field of $$37.68 	imes 10^{-4} \mathrm{~T}$$ at its center. The current through the coil is _________A.
[Given, number of turns in the coil is 100 and $$\pi=3.14$$]

Accepted Answer

$$B = {{{\mu _0}nI} \over {2R}}$$
$$37.68 	imes {10^{ - 4}} = {{4\pi  	imes {{10}^{ - 7}}100\,I} \over {2 	imes 5 	imes {{10}^{ - 2}}}}$$
$$I = {{300\,A} \over {100}}$$
$$ = 3\,A$$

Magnetism and Matter

A closely wounded circular coil of radius 5 cm produces a magnetic field of $37.68 \times 10^{-4} \mathrm{~T} at its center. The current through the coil is _________A. [Given, number of turns in the coil is 100 and \pi=3.14$]

Choose the correct answer: