Chapter 7, Problem 7.110QP

Interpretation Introduction

Interpretation:

The light which generate more electrons when blue and yellow lights are shined on a clean metal surface and the light which eject electrons with greater kinetic energy by assuming that the same total amount of energy is delivered to the metal surface by each laser and that the frequencies of the laser lights exceed the threshold frequency should be explained by using the concept of photoelectric effect.

Concept Introduction:

Albert Einstein explained famous mysterious phenomenon, called the photoelectric effect.  In the photoelectric effect, electrons are ejected from the surface of a metal when it is exposed to the light.  The incident light should be of a certain minimum frequency called the threshold frequency.  The number of electrons ejected was proportional to the intensity of the light.  The energies of the ejected electrons weren’t related to it.  Electrons weren’t ejected below the threshold frequency.

Figure.1

The Apparatus shown is used for studying the photoelectric effect.  The incident light of a certain frequency falls on a clean metal surface.  Ejected electrons are attracted toward the positive electrode.  The flow of electrons is registered by a detecting meter.  Einstein suggested that a beam of light is a stream of particles.  These “particles” of light are called photons.