Finding I3: Resistance Ratio Calculation

AI Thread Summary
The discussion centers on calculating the current I3 using the current divider rule. Two formulas are presented for I3: one involving R2 and R4, and another involving only R2 and R3. It is clarified that since R2 is not in series with R4, the correct formula is I3 = R2 / (R2 + R3) * I. When R3 is set equal to R2, this formula yields the expected result of I3 = I/2. The consensus confirms that the second formula is the appropriate choice for this scenario.
hquang001
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Homework Statement
In the figure below, how can i apply current divider to find I3 ?
Relevant Equations
[tex] Ix = \frac{Rt}{Rt +Rx} I [/tex]
163404105_973609490135196_3780337236855681454_n.jpg

Should it be I3 = \frac{(R2+R4)}{(R2+R4) +R3} I
or I3 = \frac{R2}{R2 +R3} I
 
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hquang001 said:
Homework Statement:: In the figure below, how can i apply current divider to find I3 ?
Relevant Equations:: Ix = \frac{Rt}{Rt +Rx} I

View attachment 280158
Should it be I3 = \frac{(R2+R4)}{(R2+R4) +R3} I
or I3 = \frac{R2}{R2 +R3} I
Ok i know the answer,
in this case R2 is not in series with R4 so the second answer is correct
 
If you set ##R_3=R_2## which of the two choices gives you the expected answer ##I_3=\dfrac{I}{2}##?
 
kuruman said:
If you set ##R_3=R_2## which of the two choices gives you the expected answer ##I_3=\dfrac{I}{2}##?
The second one
 
Right.
 
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