- #1

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- Homework Statement
- I need to calculate the equivalent resistance in 4 different cases

- Relevant Equations
- 1/Rep = 1/R1 + 1/R2 + ... + 1/Ri

Res = R1 + R2 + ... + Ri

R1 = 2 ohms ; R2 = 2 ohms; R3 = 1ohm

First figure:

I need to calculate the resistance between: a) A and C and b) A and B

a) R1 and R3 are in series => R13 = R1 + R3 = 3 ohms

R13 and R2 are in parallel => 1/Rp = 1/R13 + 1/R2 => Rp = 1.2 ohms

b) Here, between A and B there is only R1 so the equivalent resistance will be 1 ohm? (is this correct?)

Second figure:

I need to calculate the resistance between: a) A and C and b) B and C

a) R1 and R3 are in series => Rs = R1 + R3 = 3 ohms

But here, if we take another path: R1 and R2 parallel the result will be 1 ohm.

Which one is correct and why are they different?

b) Between B and C there is only R3 = 1 ohm.

But if we take R2 parallel with R3 => 0.66 ohms

Which one is correct?

Third figure:

I need the resistance between A and D:

R1 and R3 are in series => R1+R3 = 3 ohms

Fourth figure:

I need the resistance between A and D:

Here couldn't I take the same path as earlier and get 3 ohms or the path with R2 only for 2 ohms?

Could you please explain where I'm wrong and which one is the correct answer at each point? Thank you, in advance!

First figure:

I need to calculate the resistance between: a) A and C and b) A and B

a) R1 and R3 are in series => R13 = R1 + R3 = 3 ohms

R13 and R2 are in parallel => 1/Rp = 1/R13 + 1/R2 => Rp = 1.2 ohms

b) Here, between A and B there is only R1 so the equivalent resistance will be 1 ohm? (is this correct?)

Second figure:

I need to calculate the resistance between: a) A and C and b) B and C

a) R1 and R3 are in series => Rs = R1 + R3 = 3 ohms

But here, if we take another path: R1 and R2 parallel the result will be 1 ohm.

Which one is correct and why are they different?

b) Between B and C there is only R3 = 1 ohm.

But if we take R2 parallel with R3 => 0.66 ohms

Which one is correct?

Third figure:

I need the resistance between A and D:

R1 and R3 are in series => R1+R3 = 3 ohms

Fourth figure:

I need the resistance between A and D:

Here couldn't I take the same path as earlier and get 3 ohms or the path with R2 only for 2 ohms?

Could you please explain where I'm wrong and which one is the correct answer at each point? Thank you, in advance!