Calculating Current in a Circuit with R1 = 10 Ohms and R2 = 8 Ohms

[fan_boy17]

Homework Statement

the question is find the current through R1

R1= 10 Ohms R2=8 ohms
current source=9A
E=18V

Homework Equations

The Attempt at a Solution

I have tried removing the current source and i get a short circuit on R1 and hence i obtain a current of 2.25A

 

[dikmikkel]

What you are looking for are kirschoff's laws:
The current entering any junction is equal to the current leaving. So at the top I1 enters and use that together with the "voltage law" then you get the answer

 

[paul2211]

When using superposition on current sources, you should open, instead of shorting, circuit that branch.

That may be where your problem lies.

 

[fan_boy17]

Yes didn't realize that i needed to make the current source open circuit. thanks!

 

[DeeNos]

flowing through R1. However, this approach is incorrect as it does not take into account the presence of the current source.

To accurately calculate the current through R1, we can use Ohm's Law (V=IR) and Kirchhoff's Voltage Law (KVL).

First, we need to determine the total resistance in the circuit. We can do this by using the formula for resistors in parallel: 1/Rt = 1/R1 + 1/R2. Plugging in the values, we get: 1/Rt = 1/10 + 1/8 = 9/40. Therefore, Rt = 40/9 Ohms.

Next, we can use Ohm's Law to calculate the current through R1. Using the formula I = V/R, we get: I = 18V / 40/9 Ohms = 9/5 A = 1.8A.

Finally, to check our answer, we can use Kirchhoff's Voltage Law to verify that the voltage drop across R1 is indeed 18V. Using the formula V = IR, we get: V = 1.8A * 10 Ohms = 18V. Therefore, our answer of 1.8A for the current through R1 is correct.

In summary, to calculate the current through R1 in this circuit, we need to consider the total resistance in the circuit and use Ohm's Law and Kirchhoff's Voltage Law to solve for the current.