Determine the Plank's Constant

Objective
In this experiment, we will view the spectrum of colors found in white light and measure the wavelength of several different colors

 

Experiment  

 

 Set up the LED and rulers

 

Measure the length of color from each LEDs

 

Use the mutimeter to measure the voltage across the LEDs and multiply by (e-) to get the energy

 

Datas and results

 

 

 

 

Conclusion

 

In this experiment, we measured the wavelengths of the diffraction lights. And we graph the E vs c/lambda. The slope of the graph should be the Plank's constant and our error is about 15% which is acceptable.