Circuits problem, please please please help?
.................___{V}___..............…
.............__|________|__...........
.............|....[20ohm]......|......…
...--------|........................|-…
...|.........|__[5ohm]_{A}_|....|.....…
...|..................................…
[10ohm]..............................|…
...|..................................…
...|______+|I|I10V-_______|.......
This was the question on my final exam.. I am almost sure I flunked this part, but I would like someone to work it out.
The question asked what the readings on the voltmeter {V} and ammeter {A}
If my drawing doesn't make sense, it starts with the battery with the positive terminal facing left. Then going clockwise (and turning right) you meet a 10ohm resistor. Then turning right again, you meet two parallel resistors: a 20ohm resistor on top and a 5ohm resistor on the bottom. Then they meet again to complete the circuit.
After the 5ohm resistor is an ammeter. Between the 20ohm resistor is a voltmeter.
Update:Battery = 10V
R1 = 10 ohm
R2 = 20 ohm
R3 = 5 ohm
Comments
First solve the parallel resistance:
5 Ω || 20 Ω = (5 Ω x 20 Ω)/(5 Ω + 20 Ω) = 4 Ω
Voltage across the parallel resistors (i.e. reading on the voltmeter):
V = (10 V)(4 Ω)/(10 Ω + 4Ω) = 40/14 = 2.86 V
Current through the 5 Ω resistor (i.e. reading on the ammeter):
I = 2.86 V / 5 Ω = 0.57 A
V = 2.86 V
I = 0.57 A