Question

An alpha particle, a deuteron and a proton are moving with same momentum in a uniform
magnetic field. The ratio of their speeds will be
a-1:2:4
b-1:1:1
c-4:2:1
d-2:2:4​

Answer 1

Mass of an Alpha Particle = 4m (m1)

Mass on a deuteron = 2m (m2)

Mass on a proton = m (m3)

Momentum is constant.

=> m1v1 = m2v2 = m3v3

=> 4m(v1) = 2m(v2) = m(v3)

=> v1 : v2 : v3 = 1 : 2 : 4

Hence, the ratio of their speeds will be (a)1:2:4