A What is the equivalent resistance of the circuit shown in

A) What is the equivalent resistance of the circuit shown in the figure?(Figure 1)

B) What is the current in the 18 ? resistor?

C) What is the current in the 12 ? resistor?

D) What is the power dissipation in the 4.5 ? resistor?

resistors 12 and 22 are in parallel,

R1 = (12*22)/(12+22) = 7.76

R1*4.5 are in series, R2 = R1 + 4.5 = 12.26

R2 &18 are in parallel, so

Req = (12.26*18)/(12.26+18) = 7.29 Ohms

current is,

i = V/R = 6/18 = 0.333 A

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total current I = V/R_eq = 6/7.29 = 0.823 A

current through R1, i1 = 0.823-0.333 = 0.49

from voltage division rule, we have
current through 12 ohms resistor is,

i = 0.49*22/(12+22) = 0.317 A = 0.32 A

current throug 4.5 resistor is,

= i3 = i1 = 0.49 A

thus the power is,

P = i3^2*4.5 = 1.08045 W = 1.08 W