in Figure.3.11.   Figure.8. Diode Characteristics Figure.3.11. Diode Characteristics 3.5.1. Zener Diode: Figure.3.12. Symbol 3.5.2. Zener characteristics: Figure.3.13 3.6. Resistors: A  resistor  is a two- terminal   electronic component  that produces a  voltage  across its terminals that is  proportional  to the  electric current  passing through it in accordance with  Ohm's law