The graph shows the maximum kinetic energy of electrons emitted by a photosensitive surface as a function of the frequency of the incident radiation. The slope of this curve represents
A) the intensity of the incident radiation.
B) the maximum kinetic energy.
C) the threshold frequency.
D) Planck's constant.
E) the stopping potential.

Question

The graph shows the maximum kinetic energy of electrons emitted by a photosensitive surface as a function of the frequency of the incident radiation. The slope of this curve represents
A) the intensity of the incident radiation. 
B) the maximum kinetic energy. 
C) the threshold frequency. 
D) Planck's constant. 
E) the stopping potential.

Quizplus · Accepted Answer

The slope of this graph represents the value of Planck's constant, which relates the energy of a photon to its frequency. Thus, choice D is the correct answer. The intensity of the incident radiation does not affect the slope of the graph (choice A). The maximum kinetic energy is given on the y-axis (choice B). The threshold frequency is the frequency at which the photoelectric effect occurs, which is given by the x-intercept (choice C). The stopping potential is the voltage required to stop the flow of photoelectrons, which is not directly related to the slope of the graph.

The Graph Shows the Maximum Kinetic Energy of Electrons Emitted