# Simple Combination Circuit, Find Current

**1. The problem statement, all variables and given/known data**

Combinations of Resistors

**Im not sure if the image will show up. If the image doesn’t show up; it is similar to this picture **http://ift.tt/1cGqmed

**In the link’s picture R1 is in the correct spot, R2 is R6-5-4 and R3 is R3-2. Sorry if there is any confusion.**

Given the circuit shown below, the power supply is set to a voltage V=18.3 V, R2 = 33.2 Ω, and R3 = 46.5 Ω. Suppose you place an ammeter into the circuit and find that the current through R2 is 0.263 A. Answer the following questions:

A)What is the voltage across resistor R2? 8.74 V This is correct

B)What is the current through resistor R3? 0.188 A This is correct

C)What is the current flowing through R1? 0.451 A This is correct

D)What is the resistance of resistor R1? I NEED HELP ON THIS ONE

**2. Relevant equations**

V2 = R2 * I2

I3 = V3 / R3

I1(series)= I2 + I3 (Parallel)

R1 = V1 / I1

**3. The attempt at a solution**

A) V2 = R2 * I2 = 33.2 *.263 = 8.74

Voltage going through resistor 2 is 8.74 V

B) I3 = V3 / R3 = 8.74/46.5 = .188 A

Current going through resistor 3 is .188 A

C) I1(series)=I2 + I3 (parallel) = I1 = .188 + .263= .451 A

Current going though resistor 1 is .451 A

D) THIS IS THE PART I NEED HELP WITH!

R1 = V1 / I1 = 18.3/.451 = 40.57 ohms

This answer is not correct and I am not sure why. I thought that the way to find resistance was R= V/I. I solved for the correct current in the previous problem and we are given that V= 18.3 V in the wording of the problem.

Any help would be greatly appreciated!

http://ift.tt/1duKeoK

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