physics
posted by Nilan  please help on .
resistors of 30 ohms and 60 ohms are connected in parallel and joined in series to a 10 ohm resistor. the circuit voltage is 180 volts
I need to find
1)the voltage of the parallel circuit
2)the resistance of the complete circuit
3)the voltage across the 10 ohm resistor
4) the voltage across the parallel circuit
5) the current through the 10 ohm resistor
6) the current through the 30 ohm resistor
7) the current through the 60 ohm resistor
Can you please help with the formulas and how to set up the problem?
Thank you
You need to analyze, not formulas.
First, find the equivalent resistance of the parallelbranch.
Then, find total resistance of the circuit.
Then, find total current (voltage/totalresistance
Now, knowing total current, voltage on the parallel branch is equivalent parallelresistance x current.
then the current in the 30 ohm is voltage on parallel branch divided by 30
I will be happy to critique your thinking.
Hello again
would you please check this:
1) 20 V
2) 30 ohms
3) 60 V
4) 180 V
5) 6 A
6) 4 A
7) 2 A

E = 180 V.
R1 = 10 Ohms.
R2 = 30 Ohms
R3 = 60 Ohms
Req. = R1 + (R2*R3)/(R2+R3) = 10 + 20 =
30 Ohms.
I1 = E/Req. = 180/30 = 6A
V1 = I1*R1 = 6 * 10 = 60 V.
V2 = V3 = I*20 Ohms = 6 * 20 = 120 V.
I2 = V2/R2 = 120/30 = 4A.
I3 = V3/R3 = 120/60 = 2A.