P=10000
v1=2300
v2=230
a=v1/v2
f=50
r1=3.96
r2=0.0396
x1=15.8
x2=0.158

R=r1+a*a*r2
X=x1+a*a*x2
V2=v2*a
I=P/V2
pf=0.8
theta=acos(pf)
V1=V2+I*(R*cos(theta)+X*sin(theta))
Pi=75*V1*V1/V2/V2
Pc=I*I*R
Pl=Pi+Pc
P0=P*pf
effi=P0/(P0+Pl)*100
disp(effi)

V1=V2
Pi=75
pf2=X/sqrt(R*R+X*X)
I=P0/V1/pf2
Pc=I*I*R
Pl=Pi+Pc
P0=P*pf
effi=P0/(P0+Pl)*100
disp(effi)

I=sqrt(Pi/R)
Load=V2*I
P0=Load*pf
Pl=2*Pi
effi_max=P0/(P0+Pl)*100
disp(effi_max)