KCET 2017 Physics Solved Paper

In a hydrogen atom, energy required to excite an electron from state E1 to state Ef is
E=Ef−Ei
where energy of a state n is given by
En=

−13.6

n2

eV
E4=

−13.6

42

=

−13.6

16

=−0.85eV
and E2=‌

−13.6

22

=

−13.6

4

=−3.4eV
Therefore, Thus, energy required =2.55eV