Paraphrasing

Intro:

In 1905 Albert Einstein advanced the theory of light by discounting the conventional wave picture by accounting for the photoelectric effect. The photoelectric effect asserts that when light is shone on a metal surface, electrons are released. These electrons can then be attracted to a positively charged plate a certain distance below, causing a photoelectric current. It is best not to measure the current itself, but to measure the stopping potential (Vo), required to reduce the current to zero. The earlier wave picture is not a good representation of the photoelectric effect because it shows no photoelectric electrons being emitted if the frequency of light falls below the cutoff frequency (fc). Because of this, Einstein developed an equation off of Planck’s hypothesis of photons. He related photons energy to the energy distance between adjacent levels of a black body. The resulting equation is: E=hf (1). This lab successfully tests the effect of light laid out by Einstein.

The photoelectric is the process of electrons bouncing on a surface when the light shines on the metal surface. The electrons emitted are called photoelectrons. The photoelectric effect has been essential to explain waves and particles. More electrons were produced when the light intensity increases. A bright red light will not create a current in the metal, but a dim blue light will result a current. Different colors will result in the amount of energy they contain. Blue light has more energy than red light and yellow light is somewhere in the middle. Bright lights produce many electrons, but with the exception of a bright red light. Here is the quantum theory: E=hf, where f is the frequency and determines the energy, E of the electrons in the light beam. H is plank’s constant (h = 6.626176 x 10-34 joule-seconds). Thus, it was the purpose of the particular lab to determine plank’s constant from photoelectric effect.