Magnetic fields at two points on the axis of a circular coil at a distance of 0.05,m and 0.2,m from the centre are in the

Q: Magnetic fields at two points on the axis of a circular coil at a distance of $0.05\,m$ and $0.2\,m$ from the centre are in the ratio $8 : 1$. The radius of the coil is.....$m$

b (b) $B = \frac{{{\mu _0}}}{{4\pi }} \times \frac{{2\pi Ni{R^2}}}{{{{({R^2} + {x^2})}^{3/2}}}} $ $\Rightarrow B \propto \frac{1}{{{{({r^2} + {x^2})}^{3/2}}}}$ $ \Rightarrow \frac{8}{1} = \frac{{{{({R^2} + x_2^2)}^{3/2}}}}{{{{({R^2} + x_1^2)}^{3/2}}}} $ $\Rightarrow {\left( {\frac{8}{1}} \right)^{2/3}} = \frac{{{R^2} + 0.04}}{{{R^2} + 0.0025}}$ $ \Rightarrow \frac{4}{1} = \frac{{{R^2} + 0.04}}{{{R^2} + 0.0025}}$. On solving $R = 0.1\,m$

SECTION - A [PHYSICS - MCQ]

GSEB - English Medium

Magnetic fields at two points on the axis of a circular coil at a distance of $0.05\,m$ and $0.2\,m$ from the centre are in the ratio $8 : 1$. The radius of the coil is.....$m$

A$1$
B$0.1$
C$0.15$
D$0.2$

Diffcult

STD 11 Science
NEET
STD 12 - 4. Moving charges and magnetism
Physics

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