Question

Rc circuit

R2 7) R3 Four resistors of values R1 = 2.0 Ω, R2 = 4.0 Ω, R3-3.00, and R4° 9.0 Ω are connected across an 8.0 VDC source as shown in the above figure, what is the power dissipated in R2, the 4.00 resistor? A) 4.0 W B) 16. W C)9.0 W D) 7.1 W E) 1.0 W 8) Also calculate the voltage across R a) 1 V b) 2 V c) 3 V d) 4 V

Answer 1

first we will find equivalent resistance

Req=(R1+R2) parllel to(R3+R4)

=(4+2) parllel to(9+3)

=6 parllrl to 12

1/Req=1/6+1/12

Req=4ohm

Total Current in circuit: Itotal = Vtotal/Rtotal (using Ohms law)

Itotal=8/4

=2amps

Vn=vtotal*Rn/Rtotal

so Vn=8*4/(4+2)

Vn=5.33 V

P=v^2/R

=5.33^2/4

=7.10watt

answer is D

2)Vn=vtotal*Rn/Rtotal

=8*3/12

=2V --answer