The wavelength of the energy emitted when electron come from fourth orbit to second orbit in hydrogen is 20.397 cm. The wavelength of energy for the same transition in ${\mathrm{He}}^{+}$ is

(a) 5.099 ${\mathrm{cm}}^{-1}$             (b) 20.497 ${\mathrm{cm}}^{-1}$
(c) 40.994 ${\mathrm{cm}}^{-1}$            (d) 81.988 ${\mathrm{cm}}^{-1}$

Explanation is a part of a Paid Course. To view Explanation Please buy the course.

Difficulty Level: