Physics (Essay) Paper 2 May/June 2015

Question 7

(a) Write the de-Broglie equation.
(b)  Explain the significance of the equation.

Observation

It was not a popular question among the candidates though fairly attempted.  Most candidates were able to write the de-Broglie equation but were unable to explain the significance of the equation.  Instead they had the view that the equation was for the calculation of wavelength of a photon.          

The expected answer is:

  (a)                 =                            OR     λ   =                                                   

(b)     A particle of mass(m) moving with velocity/ speed (v) has an associated
wavelength ().  The wavelength decreases with  increase in momentum/
velocity