Hi.
I am trying to figure out if I'm wrong or the given answer is wrong.
I am to solve for I using the principle of superposition in figure 1.2.
This is my methodology:
Set all voltage sources=0.
Turn on right side voltage source. Circuit reduces to 12V voltage source and 4k resistance since the 6k is shorted. I is in the opposite direction to voltage.
V=IR==> I=V/R = 12V/4k=3mA (Now here the answer says -3mA but that would only happen when I and V are in the same direction no?)
Set all voltage sources=0.
Turn on left side voltage source. Circuit reduces to 12V voltage source and 6k resistance. This time I is in the same direction as V.
V=IR==> I=V/R = -12V/6k=-2mA (here the answer is given as 2mA but again, this would only happen when I and V are in opposite directions, no?)
Therefore by principle of superposition
I=[3+(-2)]mA= 1mA (But answer is -1mA)
Is there anything I'm missing or is the answer wrong? (I am inclined to believe the answer is not wrong as it was given in the mark scheme of an exam)