Deduce an approximate value for Planck's constant by monitoring the voltage at which an LED begins to emit light and its frequency.
Modern LEDs (light emitting diodes) cover the range from deep blue to infra-red. By monitoring the voltage at which each LED just begins to emit light a graph of energy input as a function of light emitted frequency can be plotted and an approximate value of Planck’s constant deduced.
The system is an excellent illustration of modern electronics and gives a good investigation into a difficult topic in Post-16 physics.
The LEDs are mounted in a self-contained box with voltage control and monitoring points for current and voltage. A protection resistor is included to prevent damage to the LEDs.
Complete with viewing tube but without power supply which should be approximately 5V d.c. from any laboratory source.
Product code: S600-020E