Two circular coils of radii and carry currents of

PHYSICS · Multi correct · CBSE · Physics · Moving Charges and Magnetism · Moving Charges and Magnetism

Problem

Two circular coils of radii

5\,\text{cm}

and

10\,\text{cm}

carry currents of

2\,\text{A}

. The coils have

50

and

100

turns, respectively, and their planes and centres coincide. The magnitude of the magnetic field at their common centre is: (1)

8\pi\times10^{-4}\,\text{T}

if currents in the coils are in the same sense (2)

4\pi\times10^{-4}\,\text{T}

if currents in the coils are in opposite senses (3) Zero if currents in the coils are in opposite senses (4)

8\pi\times10^{-4}\,\text{T}

if currents in the coils are in opposite senses