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The magnetic field at the center of a circular path traced by a moving electron is derived as B = μ₀qv / 2r, where q is the charge, v is the velocity, and r is the radius. Which of the following is correct about the magnetic field?

1. The magnetic field increases with higher velocity.
2. The magnetic field decreases as the radius grows.
3. The magnetic field depends directly on the charge.
4. The magnetic field does not depend on the charge.

Correct answer: The magnetic field depends directly on the charge.

Solution

The formula for the magnetic field at the center is B = (μ₀ × q × v) / (2r). From this, it is evident that the magnetic field is directly proportional to the charge q. Hence, option C is correct.

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