The Zener diode was used in its reverse bias. The Zener diode was basically used to produce a stabilized voltage output with low ripple as the load current varies. The observed load current varied between 0 mA and 10 mA. By passing a small current through the diode, close to 0 A, from a voltage source, the zener diode conducts enough current to maintain a voltage drop across Vout. Zener diode as a voltage regulator, clipping circuits are used to remove the undefined part of the signal; while clamping circuits are used to shift an input signal by an amount defined by an independent voltage