Easy MCQ +4 / -1 PYQ · JEE Mains 2023

An electron is allowed to move with constant velocity along the axis of current carrying straight solenoid.

A. The electron will experience magnetic force along the axis of the solenoid.

B. The electron will not experience magnetic force.

C. The electron will continue to move along the axis of the solenoid.

D. The electron will be accelerated along the axis of the solenoid.

E. The electron will follow parabolic path-inside the solenoid.

Choose the correct answer from the options given below:

  1. A B, C and D only
  2. B B and C only Correct answer
  3. C A and D only
  4. D B and E only

Solution

<p>The magnetic field inside a solenoid is uniform and parallel to the axis of the solenoid. When an electron moves with constant velocity along the axis of the solenoid, the angle between its velocity vector and the magnetic field is 0°.</p> <p>The magnetic force experienced by a moving charge is given by the Lorentz force formula:</p> <p>$\vec{F} = q(\vec{v} \times \vec{B})$</p> <p>Since the angle between the velocity vector and the magnetic field is 0°, the cross product term becomes zero:</p> <p>$\vec{v} \times \vec{B} = 0$</p> <p>Therefore, the magnetic force experienced by the electron is also zero:</p> <p>$\vec{F} = 0$</p> <p>As a result, the electron will not experience any magnetic force (Option B) and will continue to move along the axis of the solenoid with constant velocity (Option C).</p> <p>Thus, the correct answer is:</p> <p>B and C only</p>

About this question

Subject: Physics · Chapter: Magnetic Effects of Current · Topic: Biot-Savart Law

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