Compound Circuits and resistance in a parallel circuit

In summary, the conversation involved finding the current through R3 and R2 in a circuit with a total resistance of 9.00 Ω and a voltage of 80.0 V. The voltage across R2 and R3 was determined to be 26.67 V, and this was used to calculate the current through each resistor. The final values were found to be 2.22 A for R3 and 6.67 A for R2.
  • #1
bnosam
148
0

Homework Statement


http://imageshack.us/a/img829/1351/circuite.png
Find the current through R3 and R2.

The resistance of R2 and R3 are 3.00 Ω, so the total resistance should be 9.00 Ω.

I = 80.0 V / 9.00 Ω = 8.89 A

Homework Equations



I = E/R (I think?)

The Attempt at a Solution



Not really sure where to go from here, since this was the first question of this unit and it's a correspondence course and the book doesn't explain compound circuits past a single paragraph.

Any supplemental information or hints you can provide?

Thanks
 
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  • #2
So far, so good. What's the voltage across R2 and R3?
 
  • #3
V = I*R

V = (8.89 A) (3.00 Ω) = 26.67 V, right?
 
  • #4
bnosam said:
V = I*R

V = (8.89 A) (3.00 Ω) = 26.67 V, right?
Good! Now use that to find the current through each resistor.
 
  • #5
Doc Al said:
Good! Now use that to find the current through each resistor.

Awesome man, thanks a lot.

R3 = 26.67 V / 12.00 Ω = 2.22 A

R2 = 26.67 V / 4.00 Ω = 6.67 A
 

1. What is a compound circuit?

A compound circuit is a combination of two or more individual circuits that are connected together to form a larger circuit. It can contain both series and parallel elements.

2. How do you calculate the total resistance in a parallel circuit?

To calculate the total resistance in a parallel circuit, you use the formula RT = 1 / (1/R1 + 1/R2 + ... + 1/Rn), where RT is the total resistance and R1, R2, etc. are the individual resistances in the circuit.

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

In a series circuit, the components are connected one after the other along a single path. In a parallel circuit, the components are connected in multiple branches and the current can flow through each branch independently.

4. How does the total resistance change in a parallel circuit?

The total resistance in a parallel circuit decreases as more resistors are added. This is because the current is divided between the branches, resulting in a lower overall resistance.

5. How do you measure the resistance in a parallel circuit?

The resistance in a parallel circuit can be measured using an ohmmeter. Simply connect the ohmmeter across the circuit and it will display the total resistance. Alternatively, you can measure the individual resistances of each component and calculate the total resistance as mentioned in question 2.

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