(a) (i) Define atomic spectra.                                                           
(ii) Differentiate between emission spectra and absorption spectra.     

 

 

 

The diagram above illustrates an electron transition from energy level n = 3 to n = 1.  Calculate the:
(i)  energy of the photon;
(ii)  frequency of the photon;
(iii)  wavelength of the photon.                                                     
(c) (i)  Differentiate between soft x-rays and hard x-rays.
(ii) Draw the circuit symbol for a p-n junction diode.
(iii)  Give the reason for doping a semiconductor material.