question_answer

According to Einstein's photoelectric equation, the graph between the kinetic energy of photoelectrons ejected and the frequency of incident radiation is:                                                                   [AIPMT (S) 2004]

A)  

B)       

C)

D)       

Correct Answer: D

Solution :

Key Idea: Compare the Einstein's photo-electric equation with the equation of straight line. Einstein's photoelectric equation is

where \[\phi =\] work function of metal

Comparing above Eq. (i) with equation of a straight line

\[y=mx+c\]

we get   \[m=h,\,\,\,c=-\phi \]

Therefore, if we draw a graph between kinetic energy and frequency, then a straight line cutting the frequency axis at \[{{v}_{0}}\] and giving an intercept of \[(-\phi )\] on the kinetic energy axis, is obtained.