Question: A circular loop of radius r is placed in a uniform magnetic field B. If the magnetic field is perpendicular to the plane of the loop, what is the magnetic flux through the loop?

Options:

1. 0
2. πr²B
3. 2πrB
4. B/r

Correct Answer: πr²B

Solution:

The magnetic flux Φ through a surface is given by Φ = B * A, where A is the area. For a circular loop, A = πr², so Φ = B * πr².