Q. The ratio of the magnitude field at the centre of a current carrying coil of the radius $a$ and at a distance ‘$a$’ from centre of the coil and perpendicular to the axis of coil is
A) $\frac{1}{\sqrt{2}}$
B) $\sqrt{2}$
C) $\frac{1}{2\sqrt{2}}$
D) $2\sqrt{2}$
Explanation
(d) $\frac{B_{c}}{B_{a}} = \left( 1 + \frac{x^{2}}{a^{2}} \right)^{3/2} = \left( 1 + \frac{a^{2}}{a^{2}} \right)^{3/2} = (1 + 1)^{3/2} = 2\sqrt{2}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.