Loop C: Point F to point A has a rise of 6V, A to B has a drop of 3 x i1, and C to D has a rise of 4V.
+6-(3 x i1)+4=0
+6+4=3 x i1
10=3 x i1
i1=10/3
i1=3.33A
Point B: Currents coming toward a point are considered positive while currents going away from a point are considered negative. The algebraic sum of all currents at a point must equal zero.
i1+i2+i3=0
+3.33+2.0+i3=0
i3= -3.33-2.0
i3= -5.33
This time the negative value indicates that the current is going away from Point B. The problem asked for the value of i3 in the direction shown, so the answer is 5.33A without the negative sign.
High school Kirchoff’s voltage law question.
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Re: High school Kirchoff’s voltage law question.
Loop B Opposite Direction: Point C to point D has a rise of 4V and E to B has a rise of 2 x i2.
+4+(2 x i2)=0
2 x i2 = -4
i2= -4/2
i2= -2
So we get the same answer with either loop direction.
+4+(2 x i2)=0
2 x i2 = -4
i2= -4/2
i2= -2
So we get the same answer with either loop direction.
Re: High school Kirchoff’s voltage law question.
Thanks for the explanation. It was thorough and concise, I could see how you handled my error and explained the right way to approach the problem.
What is embarrassing is, I use to know this stuff like the back of my hand. I will have to read up and revise.
Yours Sincerely
Mark Abbott
Mark Abbott