2024 Moving Charges and MagnetismMagnetic Field due to a Circular Coil Easy Question 3 of 15 in Magnetic Field due to a Circular Coil

A tightly wound 100 turns coil of radius 10 cm carries a current of 7 A. The magnitude of the magnetic field at the centre of the coil is (Take permeability of free space as $4\pi \times 10^{-7}$ SI units):

A 4.4 mT
B 44 T
C 44 mT
D 4.4 T

The answer is A.

Solution

$B = \frac{\mu_0 N I}{2R}$ $B = \frac{4\pi \times 10^{-7} \times 100 \times 7}{2 \times 10 \times 10^{-2}}$ $= \frac{28\pi \times 10^{-4}}{2} = 14\pi \times 10^{-4}$ T $\approx 44 \times 10^{-4}$ T $= 4.4$ mT

Concept Magnetic field at centre of current loop

Magnetic Field due to a Circular Coil in past papers

15 questions from this chapter have appeared across 12 exam years.