A uniform electric field and a uniform magnetic field exist in a region in the same direction. An electron is projected with a velocity pointed in the same direction. The electron will:
Correct answer: D. Keep moving in the same direction but its speed will decrease
- A. Turn to its right
- B. Turn to its left
- C. Keep moving in the same direction but its speed will increase
- D. Keep moving in the same direction but its speed will decrease
Explanation
The magnetic force will be zero because the electron's velocity is parallel to the magnetic field. The electric force on the negatively charged electron will be opposite to the direction of the electric field, thus opposing its motion and causing it to slow down (decrease its speed).
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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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