The frequency of the first line of Balmer series in hydrogen atom is v0 Hz. The frequency v of the line emitted by a single ionized helium atom is
(2v0) Hz
(4v0) Hz
(v0/2) Hz
v0/4 Hz
v=Z2Rc1n12−1n22 v0=Rc122−132=Rc9−436 or v0=5Rc36 Further v=(2)2Rc122−132=20Rc36 vv0=4 or v=4v0