A proton and an alpha particle move in circular orbits in a uniform magnetic field.Their speeds 9:4 

A proton and an alpha particle move in circular orbits in a uniform magnetic field. Their speeds are in the ratio of 9: 4.
The ratio of radii of their circular orbits
( r p is
CBSE 2021 (Term-1)
To
3 (a)
4
4 (b)
3
10 00
9
00