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NEET PHYSICSMOVING CHARGES AND MAGNETISMEasy

Question

A strong magnetic field is applied along the direction of the velocity of an electron. The electron would move along:

A

a parabolic path

B

the original path

C

a helical path

D

a circular path

Step-by-Step Solution

  1. Identify Formula: The magnetic force (F\mathbf{F}) experienced by a charged particle moving with velocity v\mathbf{v} in a magnetic field B\mathbf{B} is given by the Lorentz force formula: F=q(v×B)\mathbf{F} = q(\mathbf{v} \times \mathbf{B}) The magnitude of this force is F=qvBsinθF = qvB \sin\theta, where θ\theta is the angle between the velocity vector and the magnetic field vector.
  2. Analyze Conditions: The problem states that the magnetic field is applied along the direction of the velocity. This implies that the angle θ\theta between v\mathbf{v} and B\mathbf{B} is 00^\circ (parallel) or 180180^\circ (anti-parallel).
  3. Calculate Force: Since sin(0)=0\sin(0^\circ) = 0 and sin(180)=0\sin(180^\circ) = 0, the magnetic force on the electron is zero: F=qvB(0)=0F = qvB(0) = 0
  4. Conclusion: Since no magnetic force acts on the electron, its state of motion remains unchanged (Newton's First Law). Therefore, it continues to move along its original path (straight line) with constant velocity.

Exam Context & Concepts Covered

This question aligns with the NEET PHYSICS syllabus, specifically targeting concepts from MOVING CHARGES AND MAGNETISM. Mastering this topic is crucial for scoring well in the upcoming medical entrance examinations. Solving conceptually related problems will help you understand the nuances of these concepts and improve your problem-solving speed.

PHYSICSMOVING CHARGES AND MAGNETISMstrongmagneticapplieddirectionvelocity

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