Plancks Constant

Seven Leds Of Different Wavelengths Mounted On A Moulded Plastic Case (142X80X40) Mm Approx, Selectable Through A Rotary Switch. The Apparatus Uses A 5V Dc Input Exterl 4Mm Sockets. To Monitor The Current And Voltage Across Each Led Additiol 4Mm Sockets Are Provided To Connect Voltmeter And Ammeter. The Operating Voltage For The Leds Can Be Adjusted With The Help Of Potentiometer. (Plancks Constant)