Given below are two statements : One is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : In an uniform magnetic field, speed and energy remains the same for a moving charged particle.
Reason (R) : Moving charged particle experiences magnetic force perpendicular to its direction of motion.
Assertion (A) : In an uniform magnetic field, speed and energy remains the same for a moving charged particle.
Reason (R) : Moving charged particle experiences magnetic force perpendicular to its direction of motion.
- (A)Both (A) and (R) are true and (R) is the correct explanation of (A)✓ Correct
- (B)Both (A) and (R) are true but (R) is NOT the correct explanation of (A)
- (C)(A) is true but (R) is false
- (D)(A) is false but (R) is true.
Answer: (A)
Solution
The magnetic force on a charged particle is , which is always perpendicular to the velocity . Since work done (force perpendicular to displacement), no work is done on the particle. Therefore, kinetic energy and speed remain constant. Both statements are true and (R) correctly explains (A).
JEE Main · 2022 · 24 Jun 2022 · Shift 1 · Single correct option