An election is projected with a velocity V into a region where there exists a uniform electric field of strength E perpendicular to a uniform magnetic field of directly B. if the electron velocity to remain constant,V must be:
Correct answer: D. Of magnitude E/B and perpendicular to both ⃑E and ⃑B
- A. Of magnitude B/E and parallel to B
- B. Of magnitude E/B and parallel to B
- C. Of magnitude B/E and perpendicular to both ⃑E and ⃑B
- D. Of magnitude E/B and perpendicular to both ⃑E and ⃑B
Explanation
If velocity must remain constant, the net force must be zero, so electric and magnetic forces must be equal.magnetic force = electric forceBQV = EQV = E / BAccording to Flemming's left-hand rule, velocity, electric field, and magnetic field, all must be perpendicular.
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About Charged Particle in a Magnetic Field
A charged particle moving through a magnetic field experiences the Lorentz force, which is perpendicular to both its velocity and the field. The motion may be circular or helical, with questions involving radius, angular frequency, time period, and work done. A stationary charge feels no magnetic force.
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