Experiment 3

The experiment showed how the zener kept the voltage at about the same as when you increased the supply voltage. . The zeneer into revesve bias. The cathode side showed how to select revrese

Expweiment 2

The anode is the longer leg and the shorter leg is cathode and increase bias is an open circuit.

The diode has .7v in forward bias in resverse bias is open circuit

Experiment 1

if the series you add them and find the total.
if it was the parellel the total resister wil be lower than lowest resistor