Add Resistors: Solve Circuit Value

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In summary, the given circuit contains 3 resistors, with the 3 ohm resistor not being in series with any of the 2 ohm resistors. To find the equivalent resistance, we must first identify the pair of resistors that are in parallel, combine them, and then look for other series or parallel pairs. In this case, the 4 and 3 ohm resistors are in parallel, with a combined resistance of 12/7 ohms. This combined resistance is then in series with the remaining 2 ohm resistor, resulting in an equivalent resistance of 26/7 ohms or approximately 2.
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magnifik
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Homework Statement



http://img8.imageshack.us/img8/4413/81107636.jpg

i'm a noob, and i am having trouble adding resistors. this circuit can be reduced to 1 resistor. what is its value?

Homework Equations


parallel: 1/Rtot=1/R1+1/R2+1/R3+1/R4
series: Rtot=R1+R2+R3+R4

The Attempt at a Solution


so i thought 3, 2, 2 added up in series and you just do 6/8+1/4, but this isn't right. =/ I'm having trouble discerning which resistors are parallel and which are in series. any help would be appreciated.
 
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  • #2
2 resistors R1 and R2 are in series if one connector of R1 is connected to a connector of R2 and nothing else is connected to these connectors. (or if you can determine that no current can flow through such a connection)

None of the resistors here is in series with any other.
The 3 ohm resistance isn't in series with any of the 2 ohm resistances because the point between the 3 ohm resistance and any of the 2 ohm resistances is also connected to the other 2 ohm resistance

2 resistors are parallels if one connector of R1 is connected to a connector of R2 and the other connector of R1 is connected to the other connector of R2. There's only 1 pair of
resistances here that's parallel.

The direction they are drawn in doesn't matter.

Once you combined those resistances, you can look again for a pair of resistances that is in series or parallel.
 
  • #3
huh? so are you saying i can disregard the 3 Ohm resistor?
i know the answer is supposed to be 2. i don't know how to get there though.
 
  • #4
magnifik said:
huh? so are you saying i can disregard the 3 Ohm resistor?
i know the answer is supposed to be 2. i don't know how to get there though.

No. I said the 3 ohm resitor isn't in series with any of the 2 ohm resistances. What you have to do is find the pair of resistances that's parallel, combine those and then look for other series of parallel pairs
 
  • #5
is 3 parallel with 4 and 2 is parallel with 2?
 

1. How do I determine the resistance value for a specific circuit?

In order to determine the resistance value for a specific circuit, you will need to use Ohm's Law, which states that resistance (R) is equal to voltage (V) divided by current (I). This means that R = V/I. You will need to measure the voltage and current in the circuit using a multimeter, and then use this formula to calculate the resistance.

2. Can I use any type of resistor in a circuit?

No, you cannot use any type of resistor in a circuit. Resistors come in different sizes, shapes, and materials, and each type has a specific purpose and resistance value. It is important to choose the right type of resistor for your circuit to ensure that it functions properly.

3. How do I connect resistors in a circuit?

Resistors can be connected in series or in parallel in a circuit. In series connection, the resistors are connected end-to-end, while in parallel connection, the resistors are connected at both ends. The type of connection will affect the overall resistance of the circuit, and it is important to understand how to calculate the total resistance in each case.

4. How do I calculate the total resistance in a series-parallel circuit?

In a series-parallel circuit, you will have a combination of resistors connected in series and in parallel. To calculate the total resistance in this type of circuit, you will need to use a combination of the series and parallel resistance formulas. First, calculate the total resistance for the series resistors, and then use this value in the parallel resistance formula to calculate the overall resistance.

5. How can I ensure that my resistors are functioning properly?

The best way to ensure that your resistors are functioning properly is to measure their resistance using a multimeter. This will allow you to check if the resistance value matches the one specified by the manufacturer. You should also make sure that the resistors are not getting too hot, as this could indicate a problem. Additionally, always double check the connections and make sure that the resistors are in the correct positions in the circuit.

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