Load Line Analysis

The output equation of fixed bias circuit is represented as

                                                V_CE  = V_CC - I_CR_C

is equation of straight line. The corresponding x and y axes intercepts can be computed through inserting suitable values equal to zero. Thus  by keeping

                                                                                I_C = 0

                                                                We have V_CE  = V_CC - (0)R_C

                                                                                 V_CE  = V_CC 

                                                Y intercept can be determined by putting

                                                 V_CE  = 0 volts       so that

                                                                        0  = V_CC - I_CR_C

                                                                        I_C= V_CC/R_C

                                                Which explains the slop of the load line.