I need help with this problem..
Picture: http://www.webassign.net/hecht/p18-86.gi…
Problem: Solve for the unknown source voltage and the power delivered by the battery on the left of the figure, if VL = 11 V.
?V ; ?W
So I know P =IV so I need the source voltage and then I could find P=(3)(V) but I am not sure how to do that. I know I have to use the node rule and all that but can't figure it out. Help, please! Thanks!
Picture: http://www.webassign.net/hecht/p18-86.gi…
Problem: Solve for the unknown source voltage and the power delivered by the battery on the left of the figure, if VL = 11 V.
?V ; ?W
So I know P =IV so I need the source voltage and then I could find P=(3)(V) but I am not sure how to do that. I know I have to use the node rule and all that but can't figure it out. Help, please! Thanks!
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First, figure out the unknown voltage by using KVL.
Let the current that flows across the 6 ohm resistor be i
Using KVL,
11V = 6i + 2*3
so i = 5/6 A
The unknown voltage is:
V = (3 - i) + 2*3 = 9 - i = 49/6 V
The power delivered by the left battery is V * I. Here I is nothing but the current flowing through the 6 ohm resistor.
P = 11V * 5/6 = 55/6 W
Ans: 49/6 V, 55/6 W
Let the current that flows across the 6 ohm resistor be i
Using KVL,
11V = 6i + 2*3
so i = 5/6 A
The unknown voltage is:
V = (3 - i) + 2*3 = 9 - i = 49/6 V
The power delivered by the left battery is V * I. Here I is nothing but the current flowing through the 6 ohm resistor.
P = 11V * 5/6 = 55/6 W
Ans: 49/6 V, 55/6 W