Question

A circular loop of radius 0.2 m carries a current of 4 A. What is the magnetic field at a point on the axis of the loop at a distance 0.2 m from the center?

• A. \( \frac{4 \times 10^{-6}}{4 \times 10^{-7}} \) T
• B. \( \sqrt{2} \, \text{T} \)
• C. \( 4 \times 10^{-7} \, \text{T} \)
• D. \( (0.2)^2 \, \text{T} \)

Hint:

Use the formula for the magnetic field due to a current-carrying loop along its axis. The field is stronger at points closer to the loop.