Class 12 NEET Physics Dual Nature of Matter and Radiation

For hydrogen atom,E−n=−

13.6

n2

eV
For ground state,n=1
∴E1=−

13.6

12

=−13.6eV
For first excited state, n=2
∴E2=−

13.6

22

=−3.4eV
The energy of the emitted photon when an electron jumps from first excited state to ground state is

Maximum kinetic energy,
Kmax=eVs=e×3.57V=3.57eV
According to Einstein’s photoelectric equation
Kmax=hυ−ϕ0
where ϕ0 is the work function and hv is the incident energy

Threshold frequency,
=1.6×1015 Hz