PSPICE program for plotting maximum power transfer theorem

The following circuit is used to plot the power vs the load resistance curve.

The PSPICE script is as follows.

MPTT grapgh
V1 1 0 DC 10
Rt 1 2 20
Vx 2 3 DC 0
RL 3 0 RMOD 1
.MODEL RMOD RES(R=1)
.STEP RES RMOD(R) 1, 100, 1
.DC V1 20 20 1
.PRINT DC V(1,2) I(RL)
.probe
.end

The resultant plot as a function of RL is shown below.