Question

MIDTERM
A linear circuit is shown below.
Pic: http://i45.tinypic.com/206flvd.png
The elements in this circuit have the following values: R1=200Ω, R2=200Ω, R3=100Ω, V1=5V, I1=0.001A and I2=0.005A
Determine the potentials at nodes A and B, assuming a ground node as shown in the figure.

(a) What is the value of voltage vA in Volts?
(b) What is the value of voltage vB in Volts?
Now let us determine if the answers you came up with satisfy the laws of physics.

What is the power (in Watts) dissipated in resistor R1?
What is the power (in Watts) dissipated in resistor R2?

Answer 1

Solution for Q1:
vA = (R2*V1 + R3*V1 + I1*R1*R3 - I2*R1*R3)/(R1 + R2 + R3)
vB = (R3*(V1 + I1*R1 + I1*R2 - I2*R1 - I2*R2))/(R1 + R2 + R3)
P_R1 = (vA-V1)^2/R1
P_R2 = (vA-vB)^2/R2
P_R3 = vB^2/R3
P_V1 = V1 * (V1-vA)/R1
P_I1 = V1 * I1
P_I2 = V1* (-I2)

Answer 2

are you sure of those equations? I just tried and they're not correct

Answer 3

va=2.84
vb=0.680
power r1=0.023328
power r2=0.023328
power r3=0.004624
power v1=0.054
power i1=0.00068
power i2=-0.0034