Question

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.

• A. Both (A) and (R) are true and (R) is the correct explanation of (A).
• 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 1

Answer: (A)

Both (A) and (R) are true and (R) is the correct explanation of (A).

Answer 2

Magnetic force
$\vec{F}$⊥$\vec V$
⇒ _ Wb_ = 0
⇒ ΔKE = 0 and speed remains constant.
The correct option is (A): Both (A) and (R) are true and (R) is the correct explanation of (A).