Question

VA ROG CHIAR AM NEVOIE DE AJUTOR LA ACEASTA PROBLEMAA,MULTUMESC!!!

Answer 1

O sa notez cu 1-sting sus, 2-drept sus, 3-sting jos, 4-sting dreapta.

Se da:
E1=E2=E3=E4=E'=10V
r1=r2=r3=r4=r'=2ohm
R=8ohm
a)k-deschis; E=?V; r=?ohm
b)k-inchis; E=?V; r=?ohm
c)k-inchis; I=?A
d)k-deschis; I=?A

Formule:
a)E12=E34=E

E12=E1+E2

E=E1+E2
E=2*E'


1/r=(1/r12)+(1/r34)

r12=r1+r2
r34=r3+r4

1/r=[1/(r1+r2)]+[1/(r3+r4)]
1/r=(r1+r2+r3+r4)/(r1+r2)(r3+r4)
r=(r1+r2)(r3+r4)/(r1+r2+r3+r4)
r=4r'²/4r
r=r'

b)Daca k-inchis, atunci E13 in serie cu E24 si E1 paralel cu E3 si E2 paralel cu E4.

E=E13+E24

E1=E3=E13
E2=E4=E24

E=E1+E2
E=2*E'


r=r13+r24

1/r13=(1/r1)+(1/r3)
1/r13=(r1+r3)/r1r3
r13=r1r3/(r1+r3), de asemenea:
r24=r2r4/(r2+r4)

r=r1r3/(r1+r3)+r2r4/(r2+r4)
r=r'²/2r'+r'²/2r'
r=r'/2+r'/2
r=2r'/2
r=r'

c) si d):
Cum observam in a) si b) avem aceleasi formule pentru E si r, astfel I va fi de asemenea acelasi:

I=E/(R+r)

Calcule:
a)E=2*10=20V
r=2ohm

b)E=2*10=20V
r=2ohm

c) si d)
I=20/(2+8)=2A