# Finding currents using Kirchhoff's laws

• Bolter
In summary, Kirchhoff's laws are two fundamental principles that are used to calculate currents and voltages in electrical circuits. The first law, also known as Kirchhoff's current law, states that the sum of all currents entering a junction must equal the sum of all currents leaving the junction. The second law, also known as Kirchhoff's voltage law, states that the sum of all voltage drops in a closed loop must equal the sum of all voltage rises in the same loop. These laws provide a systematic approach to finding currents in a circuit, and can be applied to any type of circuit. However, they may not always be completely accurate due to real-world factors. Kirchhoff's current law deals with the conservation of charge
Bolter
Homework Statement
See below to see full question
Relevant Equations
V = IR
Q = It
Here is my question that I have been trying to do

Had tried to attempt it and got there as my answers? Not particularly sure if I had done part b) right from the simultaneous equation I had to solve to get the current values

Appreciate for any help! Thanks

Delta2
Part b) looks fine, I haven't run the numbers for a) and c) but your methods look right.

Part a) and c) both are correct. (I wonder if they really give 6 marks for part a )

Bolter and etotheipi
Thank you both for taking a look at it! Appreciate the help

## 1. What are Kirchhoff's laws?

Kirchhoff's laws are fundamental principles in circuit analysis that describe the behavior of electric currents and voltages in a circuit. They are used to determine the values of currents and voltages at different points in a circuit.

## 2. How do Kirchhoff's laws help in finding currents?

Kirchhoff's laws, specifically Kirchhoff's Current Law (KCL) and Kirchhoff's Voltage Law (KVL), provide a systematic approach to analyzing circuits and determining the values of currents. KCL states that the sum of currents entering a junction in a circuit must equal the sum of currents leaving the junction. KVL states that the sum of voltages around a closed loop in a circuit must equal zero.

## 3. What is the difference between KCL and KVL?

KCL deals with the conservation of charge at a junction in a circuit, while KVL deals with the conservation of energy around a closed loop in a circuit. In other words, KCL is concerned with the flow of current, while KVL is concerned with the flow of voltage.

## 4. Can Kirchhoff's laws be applied to any circuit?

Yes, Kirchhoff's laws can be applied to any circuit, whether it is a simple circuit with only a few components or a complex circuit with multiple loops and branches. As long as the circuit is in a steady state, meaning the currents and voltages are not changing over time, Kirchhoff's laws can be used to find the values of currents.

## 5. Are there any limitations to using Kirchhoff's laws?

While Kirchhoff's laws are powerful tools in circuit analysis, they do have some limitations. They assume ideal conditions, such as no resistance in wires and no internal resistance in batteries. In reality, these ideal conditions do not exist, so the calculated values of currents using Kirchhoff's laws may not be completely accurate. Additionally, Kirchhoff's laws can become more complex to apply in circuits with a large number of components.

• Introductory Physics Homework Help
Replies
6
Views
969
• Introductory Physics Homework Help
Replies
18
Views
2K
• Introductory Physics Homework Help
Replies
28
Views
1K
• Introductory Physics Homework Help
Replies
8
Views
902
• Introductory Physics Homework Help
Replies
8
Views
1K
• Introductory Physics Homework Help
Replies
16
Views
1K
• Introductory Physics Homework Help
Replies
1
Views
205
• Introductory Physics Homework Help
Replies
3
Views
825
• Introductory Physics Homework Help
Replies
12
Views
2K
• Introductory Physics Homework Help
Replies
2
Views
896