1. Tardigrade
  2. Question
  3. Physics
  4. In a mass spectrometer used for measuring the masses of ions, the ions are initially accelerated by an electric potential V and then made to describe semicircular paths of radius R using a magnetic field B. If V and B are kept constant, the ratio (( text Charge on the ion / text mass of the ion )) will be proportional to:-

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. In a mass spectrometer used for measuring the masses of ions, the ions are initially accelerated by an electric potential $V$ and then made to describe semicircular paths of radius $R$ using a magnetic field $B$. If $V$ and $B$ are kept constant, the ratio $\left(\frac{\text { Charge on the ion }}{\text { mass of the ion }}\right)$ will be proportional to:-

AIPMTAIPMT 2007Atoms

Solution:

Radius of semicircular path
$R =\frac{ mv }{ qB }=\frac{\sqrt{2 mqV }}{ qB }$
As $V$ and $B$ are constant so
$R \alpha \frac{\sqrt{ mq }}{ q } $
$\Rightarrow \frac{ q }{ m } \propto \frac{1}{ R ^{2}}$