Photon Energy Array 

Seven LED's of different wavelength mounted on an acrylic base bended at their edge to stand it. LED's are selectable through a rotary switch surrounded by LED's. The apparatus uses a 5V DC external voltage via. 4mm colour coded sockets indicated with 5V and 0V respectively. To monitor the current and voltage across each LED 4mm sockets are provided to connect voltmeter and current meter indicated with 'V' and 'A' respectively. The operating voltage for the LED's can be adjusted with the help of potentiometer fitted on the base. Students can measure the threshold voltage.