Teaching HTET TGT Level 2 - 2024 Mock Test Physics Moving Charges and Magnetism Magnetic Field on the Axis of a Circular Current Loop
A coil having N turns is wound tightly in the form of a spiral with inner and outer radii a and b respectively. When a current I passes through the coil, the magnetic field at the center is
1
\(\frac{\mu_0 \mathrm{NI}}{b}\)
2
\(\frac{2 \mu_0 \mathrm{NI}}{a}\)
3
\(\frac{\mu_0 \mathrm{NI}}{2(b-a)} \ln \frac{b}{a}\)
4
\(\frac{\mu_0 \mathrm{IN}}{(b-a)} \ln \frac{b}{a}\)