Question

$H^{+},H{e}^{+}$ and $O^{++}$ ions having same kinetic energy pass through a region of space filled with uniform magnetic field B directed perpendicular to the velocity of ions. The masses of the ions $H^{+},H{e}^{+}$ and $O^{++}are$ respectively in the ratio 1:4:16 . Choose the correct statement.

• A. $H^{+}$ ions will be deflected most
• B. $O^{++}$ ions will be deflected least
• C. $H^{+}$ and $O^{++}$ ions will suffer different deflections
• D. All ions will suffer the same deflection

Answer 1

The correct option is A $H^{+}$ ions will be deflected most

$r\propto \frac{\sqrt{m}}{q}\Rightarrow r_H:r_{He}:r_0=\frac{\sqrt{1}}{1}:\frac{\sqrt{4}}{1}:\frac{\sqrt{16}}{2}=1:2:2$
Radius is smallest for $H^{+}$, so it is deflected most.