Question

According to Einstein's photoelectric equation, the plot of the kinetic energy of the emitted photoelectrons from a metal versus the frequency of the incident radiation gives a straight line, whose slope ______.

Options

• depends both on the intensity of the radiation and the metal used

• depends on the intensity of the radiation

• is the same for all metals and independent of the intensity of the radiation

• depends on the nature of the metal used

Answer 1

According to Einstein's photoelectric equation, the plot of the kinetic energy of the emitted photoelectrons from a metal versus the frequency of the incident radiation gives a straight line, whose slope is the same for all metals and independent of the intensity of the radiation.

Explanation:

According to Einstein's photoelectric equation,

`"h"nu = "h"nu_0 + 1/2"m"v_("max"^2)`

or `1/2"m"v_("max"^2) = "h"nu - "h"nu_0`    ...(i)

The equation of a straight line in intercept form is given by

y = mx + c ...(ii)

Comparing the equations (i) and (ii), we get
m = h

Therefore, slope of the plot is equal to Planck's constant. Hence, the plot is same for all metals and independent of the intensity of the radiation.