An electron is moving north in a region when the magnetic field is south. The magnetic force exerted on the electron is:
Correct answer: A. Zero
- A. Zero
- B. Up
- C. Down
- D. East
Explanation
F = qvB sin θ, where R is a magnetic force, q is the charge, B is the magnetic field, v is the velocity, and θ is the angle between the directions of the magnetic field and the velocity. In this case, velocity is towards the north, and the magnetic field is towards the south, so θ is 180. sin(180) is zero, so F is zero.The magnetic force can't accelerate the electron but can change the direction of the electron. As the direction of the magnetic field is antiparallel to the motion of the electron, the electron will continue to travel with constant velocity without altering its path.
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About Electromagnetism
Magnetic flux density and magnetic flux describe the strength of a magnetic field and the field passing through a surface. A charged particle moving through a magnetic field experiences a force perpendicular to its velocity and may follow circular or helical motion, depending on the angle between velocity and field.
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