An electron enters a region where the electric field 'E' is perpendicular to the magnetic field 'B'. It will suffer no deflection if:
Correct answer: B. E=vB
- A. E=evB
- B. E=vB
- C. B=eE/v
- D. E=evB/2
Explanation
For the electron to pass undeflected, the electric force (Fₑ = qE) must be equal in magnitude and opposite in direction to the magnetic force (Fₘ = qvB). Equating the magnitudes, qE = qvB, which simplifies to E = vB.
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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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