A proton, an electron, and a Helium nucleus, have the same energy. They are in circular orbits in a plane due to magnetic field perpendicular to the plane. Let $\mathrm { r } _ { \mathrm { p } } , \mathrm { r } _ { \mathrm { e } }$ and $\mathrm { r } _ { \mathrm { He } }$ be their respective radii, then, (1) $r _ { e } > r _ { p } = r _ { H e }$ (2) $r _ { e } < r _ { p } = r _ { H e }$ (3) $\mathrm { r } _ { \mathrm { e } } < \mathrm { r } _ { \mathrm { p } } < \mathrm { r } _ { \mathrm { He } }$ (4) $r _ { e } > r _ { p } > r _ { H e }$
A proton, an electron, and a Helium nucleus, have the same energy. They are in circular orbits in a plane due to magnetic field perpendicular to the plane. Let $\mathrm { r } _ { \mathrm { p } } , \mathrm { r } _ { \mathrm { e } }$ and $\mathrm { r } _ { \mathrm { He } }$ be their respective radii, then,\\
(1) $r _ { e } > r _ { p } = r _ { H e }$\\
(2) $r _ { e } < r _ { p } = r _ { H e }$\\
(3) $\mathrm { r } _ { \mathrm { e } } < \mathrm { r } _ { \mathrm { p } } < \mathrm { r } _ { \mathrm { He } }$\\
(4) $r _ { e } > r _ { p } > r _ { H e }$