Graphical Method of Finding Operating point/ Q-point

Fig 1 Circuit

Fig 2 Characteristic curve

Now draw load line: Load line comes from KVL equation

   I_D = (V1-V_D) / R1 ...equation 1

  put  I_D=0   in equation 1

equation 1  becomes V_D=V1=10 (eqA)

Now put V_D=0 in equation 1

  equation 1 becomes  I_D= V1/1000

  I_D = 10mA ( eqB)

Mark  I_D=10mA  and  V_D=10V  on the characteristic curve and join these two points.

Fid 3 Q-point at the intersection of Load Line and Characteristic Curve