Calculate the equivalent resistance

AI Thread Summary
To calculate the equivalent resistance of the circuit with resistors of 3.2 ohms, 7.1 ohms, and 5.8 ohms, it is important to identify their configuration. The resistors 7.1 ohms and 5.8 ohms are in series and should be added together first. This combined resistance is then in parallel with the 3.2 ohm resistor. The correct approach involves dealing with two resistances at a time, ensuring accurate calculations. Understanding the arrangement of resistors is crucial for determining the overall equivalent resistance.
Sylvia
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Homework Statement


screen_shot_2015-02-01_at_1.34.51_pm.png

Ignore the internal resistance of the battery and assume it is merely a battery. Calculate the equivalent resistance of the circuit.

Homework Equations


1/Req = 1/R + 1/R ... (parallel)
Req = R + R ... (series)

The Attempt at a Solution


I know this is fairly simple but I don't understand how you would calculate the equivalent resistance for the three resistors (3.2 ohms, 7.1 ohms, 5.8 ohms). I assumed they were in series and simply added them, and then added 1.0 ohms and 4.5 ohms to get the total resistance. I think this is wrong, can someone explain how you would go about calculating the Req?
 
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Sylvia said:

Homework Statement


screen_shot_2015-02-01_at_1.34.51_pm.png

Ignore the internal resistance of the battery and assume it is merely a battery. Calculate the equivalent resistance of the circuit.

Homework Equations


1/Req = 1/R + 1/R ... (parallel)
Req = R + R ... (series)

The Attempt at a Solution


I know this is fairly simple but I don't understand how you would calculate the equivalent resistance for the three resistors (3.2 ohms, 7.1 ohms, 5.8 ohms). I assumed they were in series and simply added them, and then added 1.0 ohms and 4.5 ohms to get the total resistance. I think this is wrong, can someone explain how you would go about calculating the Req?

I'm afraid you're wrong. All of them aren't in series. See the figure I've uploaded. What can you infer from that? Always deal with 2 resistances at a time. Don't involve 3 together.
 

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I see what you are saying, since 7.1 and 5.8 are in series, they must be added together? And then added in parallel to 3.2?
 
Sylvia said:
I see what you are saying, since 7.1 and 5.8 are in series, they must be added together? And then added in parallel to 3.2?
You got that right mate!
 
thanks!
 
Sylvia said:
thanks![/QUOT
Glad I could help! :-)
 
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