Statement 1: If a proton and an `alpha`-particle enter a uniform magnetic field perpendicularly with the same speed, the time period of revolution of `alpha`-particle is double than that of proton.
Statement 2: In a magnetic field, the period of revolution of a charged particle is directly proportional to the mass of the particle and inversely proprotional to the charge of particle.

Options

A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion
C. If assertion is true but reason is false.
D. If the assertion and reason both are false.

Answer

B

Explanation

Time period , T = `(2n m)/(Bq)` as `((m)/(q))_(alpha) = 2 ((m)/(q))_(p) implies T_(alpha) = 2T_(p)`
Also `T prop m` , then `T_(alpha) = 4 T_(p)` which is not the case.