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An electron is projected with uniform velocity along the axis inside a current carrying long solenoid. Then : (1) the electron will be accelerated along the axis. (2) the electron will continue to move with uniform velocity along the axis of the solenoid. (3) the electron path will be circular about the axis. (4) the electron will experience a force at 45° to the axis and execute a helical path.
- (1)
- (2)
- (3)
- (4)
Correct answer: (2)
Solution
Inside a long solenoid, the magnetic field is uniform and parallel to the axis, which means that a charged particle like an electron moving along that axis will not experience any magnetic force acting on it. Therefore, it will continue to move with uniform velocity.
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