Question

How do we know for sure that only one of the plots pictured as shown could be a correct graph representing the photoelectric effect for some metal ?

• A. All graphs like this must have the same y-intercept
• B. All graphs like this must have the same x-intercept
• C. All graphs like this must have the same slope
• D. All graphs like this must tilt downward
• E. More than one of these graph could correctly represent the photoelectric effect

Answer 1

The correct option is C All graphs like this must have the same slope

Using $K.E_{max}=h\nu -\varphi$

Thus $K.E_{max}$ Vs $\nu$ graph for a certain metal has constant slope i.e $h$. Hence all the graphs like this must have the same slope.Thus option C is correct.