- #1
brentwoodbc
- 62
- 0
Homework Statement
whats are the readings at the voltmeter and the ampmeter?
You can see my work, I got V=14.74? and I=0.72A? I need help.
thanks.
Volt/amp Question: You Got V=14.74? I=0.72A? Need Help
- Thread starter brentwoodbc
- Start date
In summary, the conversation is about a circuit problem where the person is trying to find the readings at the voltmeter and ammeter. They make a mistake in their calculation and ask for help. Another person suggests using KCL equations to solve the circuit, and the original person gets stuck.
whats are the readings at the voltmeter and the ampmeter?
You can see my work, I got V=14.74? and I=0.72A? I need help.
thanks.
- #2
tyco05
- 161
- 0
From what I can tell your equivalent resistances are ok.
If the supply is 12V - YOUR calculation for current gives you the current through R1.
This splits at the next junction - in inverse proportion to the resistances of R2 and R3.
If the supply is 12V - YOUR calculation for current gives you the current through R1.
This splits at the next junction - in inverse proportion to the resistances of R2 and R3.
- #3
brentwoodbc
- 62
- 0
I made a mistake on the resistors on my paper (so that's wrong) here's what tried.
I simplified the resistors and got 20/3 ohms plus 10ohms = 16.67ohms
then I found voltage
current
v=ir
14=Ix16.67
I=0.84 amps.
But that is the circuits current how do you find it at the metre? same sort of thing is confusing me with the voltmeter.then I went back to the volt meter with the 20 Ohm resistor so
v=IR
v=.84x20
v=16.8Volts?
I simplified the resistors and got 20/3 ohms plus 10ohms = 16.67ohms
then I found voltage
current
v=ir
14=Ix16.67
I=0.84 amps.
But that is the circuits current how do you find it at the metre? same sort of thing is confusing me with the voltmeter.then I went back to the volt meter with the 20 Ohm resistor so
v=IR
v=.84x20
v=16.8Volts?
- #4
berkeman
Mentor
- 68,299
- 22,022
I don't see simplificcation solving this circuit. Just write the 2 KCL equations and solve them simultaneously...
- #5
brentwoodbc
- 62
- 0
berkeman said:
how do you do that, so you find current and voltage and plug into
i1+i2+i3...=0
v1+v2+v3=0
Im stuck.
- #6
berkeman
Mentor
- 68,299
- 22,022
brentwoodbc said:
There are two summing nodes that I see where I would write the 2 KCL equations (sum of currents into a node must equal zero). The first node is between the two 10 Ohm resistors and the Ammeter, and the second node is on top of the final 20 Ohm resistor.
Write those two equations, and you should be able to solve the circuit. It's true that the voltage drop across an ideal ammeter is zero, so you can probably collapse the circuit and solve, but since they are asking for the I and V, my first instinct would be just to solve the full KCL, and recognize the simplification later.
FAQ: Volt/amp Question: You Got V=14.74? I=0.72A? Need Help
What is the voltage of the circuit?
The voltage of the circuit is 14.74 volts.
What is the current of the circuit?
The current of the circuit is 0.72 amps.
Are these values correct?
Yes, these values are correct. They have been provided in units of volts and amps, which are standard units for measuring voltage and current.
How do I calculate the resistance of the circuit?
To calculate the resistance of the circuit, you can use the formula R = V/I, where R is resistance, V is voltage, and I is current. In this case, the resistance would be 14.74/0.72 = 20.47 ohms.
Can you explain the relationship between voltage and current in this circuit?
In this circuit, the voltage and current have a direct relationship. This means that as the voltage increases, the current also increases, and vice versa. This relationship is described by Ohm's law, which states that V = I/R, where V is voltage, I is current, and R is resistance. So, if the voltage is doubled, the current would also double, and if the current is halved, the voltage would also be halved.