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

Answer

B

Explanation

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