In a mass spectrometer used for measuring the masses of ions, the ions are initally accelearted by an electric potential `V` and then mole to describe semicircular paths of radius `R` using a magnetic field `B`. If `V` and `B` are kept cosntant, the ratio `(("charge on the ion")/("mass of the ion"))` will be porportional to

Options

A. `1//R`
B. `1//R^(2)`
C. `R^(2)`
D. R

Answer

B

Explanation

`r = (1)/(B) sqrt((2mV)/(q)) implies (q)/(m) = (2V)/(B^2 R^2) implies (q)/(m) prop (1)/(R^2)`