Light Emitting Diodes (LED)
A CIPT Lab Exercise in Modern Physics
Light emitting diodes (LEDs) are increasingly being used as indicators in electronic devices and as efficient light sources such as traffic lights. Using super-bright LEDs, students investigate the conversion of electrical energy into light and vice versa. By measuring and comparing the energy lost by each electron with the frequency of the emitted light for several LED colors students estimate Plank's constant, a fundamental number of quantum mechanics.
Regents Physics, Engineering
Two 45-minute class periods.
Light Emitting Diodes is a kit available from the CIPT
Equipment Lending Library, www.cns.cornell.edu/cipt/. It is
also available commercially from West Hill Biological
Price: No Charge