-If Vs = 20 V, R1 = 10 kΩ, R2 = 50 kΩ and R3 = 15 kΩ in Figure 6 -1, PR2 equals .
A)8.63 mW
B)18.6 mW
C)2.30 mW
D)7.64 mW

Question

-If Vs = 20 V, R1 = 10 kΩ, R2 = 50 kΩ and R3 = 15 kΩ in Figure 6 -1, PR2 equals .
A)8.63 mW 
B)18.6 mW 
C)2.30 mW 
D)7.64 mW

Quizplus · Accepted Answer

To find the power across R2 (PR2), first calculate the total resistance in the series circuit: Rt = R1 + R2 + R3 = 10 kΩ + 50 kΩ + 15 kΩ = 75 kΩ. The total current (I) is Vs / Rt = 20 V / 75 kΩ = 0.000267 A. The voltage across R2 (V2) is I * R2 = 0.000267 A * 50 kΩ = 13.35 V. The power across R2 (PR2) is V2^2 / R2 = (13.35 V)^2 / 50 kΩ = 2.30 mW.

-If Vs = 20 V, R1 = 10 KΩ, R2