How to find currents and voltages in circuits

In summary, the battery is connected to the resistor 1, which is connected to the wire. The wire then splits into two paths and goes to the two resistors. The first resistor is in series with the battery and the second resistor is in parallel with the battery. The total resistance is 70 ohms.
  • #1
chase222
12
1
I have to find the Requivalent and all of the currents and voltages in the circuit below.

l------------Resistor 1----l---------l
l l l
battery l l
l Resistor 2 Resistor 3
l l l
l l l
-----------------------------------l

My picture is not showing up right, so I'll try to describe it. The battery is on the left and the wire moves up to the right where resistor 1 is. The wire continues, but splits into two paths (making a parallel). The wire turns to the right, where resistor 2 is, but if you keep going straight and then turn right, that's where resistor 3 is.

they give us the following:
R1=40 ohms
R2=60 ohms
R3=60 ohms
Vtotal=120 V

I am not sure where to even start. I know V=IR, and I-V/R, but I don't know how to find the other numbers. I also know that in a series, current stays the same while voltage changes, while in parallel, current changes, while voltage stays the same.

I also know that for series, the Req= R1+R2, while in a parallel, 1/Req=1/R1+1/R2

I just can't figure out the numbers when you have a parallel in a series. Can you help me get started?
 
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  • #2
The two resistors that are in parallel are equivilent to a resisitor with the resistance of R where (1/R)= (1/60)+(1/60) which would be 30 ohms and then that equivilent resistor is in series with the first resistor so don't you just add them together so the total resistance would be 70 ohms?
 
  • #3
I agree with Yapper .. By your description, it sounds like R2 & R3 are in parallel, so 60ohm || 60ohm = 30 ohms. The 30ohms is then in series with R1. So Req = R1 + R2 || R3

Do you know how to determine all the currents and voltages in your circuit, from here?
 
  • #4
No, I don't. Could you explain it to me?
 
  • #5
Could you creat a drawing in paint, so the image would be easier to work with? That way, you might receive more help.
 

1. How can I determine the direction of current flow in a circuit?

To determine the direction of current flow in a circuit, you must first identify the positive and negative terminals of the power source. Current flows from the positive terminal towards the negative terminal. You can also use a multimeter to measure the direction of current flow.

2. What is the difference between series and parallel circuits?

In a series circuit, all components are connected in a single loop, meaning that the current flows through each component in order. In a parallel circuit, the components are connected in multiple branches, allowing the current to flow through each branch simultaneously.

3. How can I calculate the voltage in a circuit?

To calculate the voltage in a circuit, you can use Ohm's law, which states that voltage (V) is equal to current (I) multiplied by resistance (R). The formula is V = I x R. You can also use a multimeter to measure the voltage in a circuit.

4. What is the difference between AC and DC circuits?

AC (alternating current) circuits have a constantly changing polarity, meaning that the current flows in both directions. DC (direct current) circuits have a constant polarity, meaning that the current only flows in one direction. Most household circuits use AC, while batteries use DC.

5. How can I calculate the total resistance in a series or parallel circuit?

In a series circuit, the total resistance is equal to the sum of the individual resistances. In a parallel circuit, the total resistance is calculated using the inverse of the sum of the reciprocals of each individual resistance. You can also use a multimeter to measure the total resistance in a circuit.

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