Question

Va rog sa ma ajutati ​

Answer 1

a) R2 si R3 in paralel

$\frac{1}{r2} + \frac{1}{r3} = \frac{1}{rp}$

$\frac{1}{40} + \frac{1}{10} = \frac{5}{40}$

5Rp=40 => Rp=8

Rp si R1 in serie Rp+R1=8+20 =28

Re=28

b) I(R+r)=E

I(28+2)=30

I×30=30 => I= 1A

c) U=R1×I

U=20 V

P1=U×I

P1=20×1 =20 W