Question

Pas cu pas, daca este posibil.

Answer 1

Es=nE=4R

Ep=E

rp=r/n=r/4

rs=nr=4r

Is=Es/(R+rs)=4E/(R+4r)

Ip=Ep/(R+rp)=E/(R+r/4)

Ps=Pp=P=12,8 W

Ps=RIs²=16E²R/(R+4r)²

Ps=12,8=>16E²R/(R+4r)²=12,8<=>E²R=0,8(R²+16r²+8Rr)<=>E²R=0,8R²+12,8r²+6,4Rr (1)

Pp=RIp²=E²R/(R+r/4)²

Pp=12,8=>E²R/(R+r/4)²=12,8<=>E²R=12,8(R²+r²/16+Rr/2)<=>E²R=12,8R²+0,8r²+6,4Rr (2)

(1)-(2)=>0=-12R²+12r²=>R=r

E²R=0,8R²+12,8R²+6,4R²=20R²=>E²=20R

I=E/(R+r)=E/2R

P₁=RI²=R*E²/4R²=20R/4R=5 W