Two particles A and B having equal charges `+6C`, after being accelerated through the same potential differences, enter a region of uniform magnetic field and describe circular paths of radii `2cm` and `3cm` respectively. The ratio of mass of A to that of B is

Options

A. `4//9`
B. `9//5`
C. `1//2`
D. `1//3`

Answer

A

Explanation

`r = (sqrt(2mk))/(qB) = r = (1)/(B) sqrt((2mV)/(q))`
`implies r prop sqrtm implies (2)/(3) = ((m_(A))/(m_(B)))^(1/2) implies (m_(A))/(m_(B)) = (4)/(9)`