Question 294: Magnetism and Matter

Question

A wire of length $$314 \mathrm{~cm}$$ carrying current of $$14 \mathrm{~A}$$ is bent to form a circle. The magnetic moment of the coil is ________ A $$-\mathrm{m}^{2}$$. [Given $$\pi=3.14$$]

Accepted Answer

$$R = {l \over {2\pi }} = {{314} \over {2 	imes 3.14}} = 50$$ cm
$$\mu  = \pi {R^2}i$$
$$ = 14 	imes 3.14 	imes {(0.5)^2}$$
$$ = 11$$ A-m
2

Magnetism and Matter

A wire of length $314 \mathrm{~cm} carrying current of 14 \mathrm{~A} is bent to form a circle. The magnetic moment of the coil is ________ A -\mathrm{m}^{2}. [Given \pi=3.14$]

Choose the correct answer: