Experimental procedure of Planks constant experiment.

1. Set the apparatus and switch on the button.
2. Put toggle switch on current.
3. Check that dark current is zero.
4. Switch the lamp on. Wait a while it takes some time to warm.
5. Set the light intensity near to maximum.
6. Note that the intensity much be in that's range that current does not exceed the display range.
7. You can not change the intensity while taking calculation.
8. Set the voltages direction switch to positive polarity.
9. Put current knob at X 0.1
10. Record the values of voltages and current each time.
11. Now set the voltage direction to negative polarity.
12. Record the values of voltages and corresponding currents each time.
13. Above steps provide data to plot graph I.V
14. Fill the observation and calculation data and plot the necessary graphs.