A kirchoff's law question with multiple batteries

[Chester8990]

Homework Statement

To find the voltage at the 5 ohms resistor.

Homework Equations

V=IR
Kirchoff's first and second law

The Attempt at a Solution

The attempt was simply too long
I ended up with a voltage of 6.5V on the 5 ohm resistor...
Please help me, I have been stuck in this same question for two weeks.
What I wasn't confident with was the three batteries too...

 

[NascentOxygen]

Could I suggest that you do yourself a favour and resolve to never refer to a voltage "at" any element? By always referring to "a voltage across" an element, or to a "voltage between two points" you will be giving yourself a subtle reminder of how you must go about determining the parameter.

So, what approach will you use for determining the voltage across the resistor in question?

 

[gneill]

You'll have to show an attempt before we can know how to help. Them's the rules.

As a suggestion, write a KCL node equation for the node where all the resistors come together. Choose the bottom node as the ground reference.

 

[Chester8990]

never mind guys i solved it, thank you

 

[asteriatic]

Hello,

Kirchoff's laws are fundamental principles in circuit analysis that allow us to understand the behavior of complex circuits with multiple components and power sources. It sounds like you are having trouble applying these laws to a specific circuit problem involving multiple batteries and a 5 ohm resistor.

First, let's review Kirchoff's first law, also known as the junction rule. This law states that the sum of currents entering a junction in a circuit must equal the sum of currents leaving that junction. This means that the current flowing through the 5 ohm resistor must be equal to the sum of the currents coming from the batteries.

Next, let's look at Kirchoff's second law, also known as the loop rule. This law states that the sum of voltage drops around a closed loop in a circuit must equal the sum of voltage sources in that loop. This means that the voltage drop across the 5 ohm resistor must be equal to the sum of the voltage sources in the circuit.

To solve this problem, you will need to apply both of these laws in conjunction. Start by identifying all the junctions and loops in the circuit. Then, use Kirchoff's first law to write an equation for each junction, setting the sum of the currents entering the junction equal to the sum of the currents leaving the junction. Next, use Kirchoff's second law to write an equation for each loop, setting the sum of the voltage drops equal to the sum of the voltage sources.

You should end up with a system of equations that you can solve to find the voltage at the 5 ohm resistor. Remember to take into account the direction of current flow and the polarity of the batteries when writing your equations.

If you are still having trouble, try breaking down the problem into smaller parts and solving them individually before combining them to find the final solution. Also, make sure to double check your calculations and equations to ensure they are correct.

Don't get discouraged, solving circuit problems can be challenging but with practice and a good understanding of Kirchoff's laws, you will be able to find the solution. Good luck!