- #1
h2obc33
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Homework Statement
A circuit is constructed with five resistors and one real battery as shown above right. We model. The real battery as an ideal emf V = 12 V in series with an internal resistance r as shown above left. The values for the resistors are: R1 = R3 = 57 Ω, R4 = R5 = 75 Ω and R2 = 133 Ω. The measured voltage across the terminals of the batery is Vbattery = 11.62 V.
1) What is I1, the current that flows through the resistor R1?
Homework Equations
Ohm's Law V=IR
Kirchoff's Laws: At Junction Iin = Iout and loop ΣVn=0
The Attempt at a Solution
To solve for I1 I did Vb/Requivalent. That would be R345 = R3+R4+R5 then I1 = Vb/(R1+(1/R345+1/R2)^-1) = 87mA
I got the message "It looks like you've calculated the current through R1 by dividing the emf of the battery (12 V) by the equivalent resistance of the external resistances in the circuit. This is not quite right. Look at the circuit more carefully to correct your mistake."
I made sure to used 11.62V instead of 12V so I still don't understand what I did wrong.