Question

Which of the following graph is correct between maximum kinetic energy vs frequency plotted for three different materials photo-emissions?

• A.
• B.
• C.
  
• D.

Answer 1

The correct option is D

According to Einstein's Photo-electric effect,
$E=E_o+K.E_{max}$ = $h\nu =h{\nu }_o+K.E_{max}$
where $E_o$ is the work function E = Incident radiation
comparing the equation with equation of straight line y = mx + c
$K.E_{max}=h\nu -h{\nu }_o$
So, intercept is $-h{\nu }_o$
Threshold frequency is the minimim frequency required for photo - emissions which cannot be negative.
So, larger the wavelength larger will be the kinetic energy.
Since work function of different metals is different, Hence D is the corect answer.