Planck'S Constant Determination Box - Eisco

This apparatus is designed to determine the approximate value of Planck's constant, using a range of LED's of known wavelength, to allow the electron/photon energy to be calculated. There are 7 LED's covering the light range from deep blue at 470nm to near IR at 940nm, mounted on a box with 4mm sockets for attachment to a voltmeter and ammeter for voltage and current measurements. 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 constantcan be deduced. Requires a 9V d.c. power supply (standard lab power supply), Voltmeter (0-9 Volts), Ammeter (20mA) and 6 banana plug connecting leads. Plastic viewing tube included. Measures 20.3cm wide, 12cm long and 2.5cm tall.