K.C.S.E Physics Q & A - MODEL 2006PP2QN10&11

K.C.S.E Physics Q & A - MODEL 2006PP2QN10&11

​What is meant by the term work function?
If the frequency of the illuminating radiation is just equal to the threshold frequency of the surface explain why no photoelectric effect is observed

ANSWERS

• Work function of a metal is the minimum energy required to set free (release) an electron from the surface of the metal                                          
•  Threshold frequency K.E of electron = 0 hence velocity of the electron would be zero;      (No motion) thus photo electric effect cannot be observed