Finding Resistance Between A & B: Solved

[n77ler]

[SOLVED] Finding Resistance

Homework Statement

A number of resistors of values R1 = 3.8 Ω, R2 = 80.0 Ω, and R3 = 20.0 Ω are connected as shown in the figure. What is the resistance between points A and B?

Homework Equations

The Attempt at a Solution

Im confused because all I've been calculating is the equivalent resistance, what is the difference between the two?

 

[berkeman]

Homework Statement

A number of resistors of values R1 = 3.8 Ω, R2 = 80.0 Ω, and R3 = 20.0 Ω are connected as shown in the figure. What is the resistance between points A and B?

Homework Equations

The Attempt at a Solution

Im confused because all I've been calculating is the equivalent resistance, what is the difference between the two?

They are just asking for the equivalent resistance of that network, as seen at the entry points A & B. Just use your series & parallel combination rules to reduce the network to a single (equivalent) resistor between A & B, and you will have your answer.

 

[n77ler]

ok thank-you

 

[Mike Cookson]

The Four R1 and R3 are in series thus those five resistors to the right can be combined by adding the value...(4*3.8+20)=35.2Ω
That resistance is in parallel with the R2 thus the combination of the five and this resistor is equal to 1/(1/35.2+1/80) = 24.4Ω (3sf)
Now the total becomes this plus 2*R1

Total = 24.4+3.8*2 = 32.0Ω (3s.f.)

Just incase you were still stuck, that and I like to go back to some easy electronics now and again to remind me that my head hasn't exploded :)

 

[Snazzy]

You shouldn't give out the answers. We're not here to give solutions, but rather how to figure out a problem.

 

[Mike Cookson]

My Apologies, I was only going from what I saw in the rest of the forum.