Electricity and Kirchhoff's Laws

In summary: The current flowing from the 10V battery can be found by using Ohm's Law (V = IR) and Kirchhoff's Laws (current entering a junction = current leaving junction and algebraic sum of emfs = sum of all potential drops). By plugging in the given values, we can find that the current is 1.56 A.
  • #1
Pulser18
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Homework Statement



Given two batteries in parallel, one of 10V and 5Ω, and the other of 5V and 2Ω, which is attached to a 3Ω resistor, find the current that flows from the 10V battery, if the system described above is connected to a 20 resistor.

Homework Equations



Kirchhoff's two laws : (1) Current entering a junction = current leaving junction, (2) Algebraic sum of emfs = sum of all potential drops;

V = IR

The Attempt at a Solution



I think I used the laws correctly, and ended up with a final answer of 1.56 A. My attempt is attached below (the 2nd photo).

Thing is, I'm not sure if this is correct...
 

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  • #2
Pulser18 said:

Homework Statement



Given two batteries in parallel, one of 10V and 5Ω, and the other of 5V and 2Ω, which is attached to a 3Ω resistor, find the current that flows from the 10V battery, if the system described above is connected to a 20 resistor.

Homework Equations



Kirchhoff's two laws : (1) Current entering a junction = current leaving junction, (2) Algebraic sum of emfs = sum of all potential drops;

V = IR

The Attempt at a Solution



I think I used the laws correctly, and ended up with a final answer of 1.56 A. My attempt is attached below (the 2nd photo).

Thing is, I'm not sure if this is correct...

Your solution looks fine.
 

FAQ: Electricity and Kirchhoff's Laws

What is electricity and how does it work?

Electricity is the flow of electric charge through a conductor. It works by the movement of electrons, which are negatively charged particles, from one atom to another. This flow of electrons creates an electrical current that can power various devices and systems.

What are Kirchhoff's Laws and why are they important?

Kirchhoff's Laws are fundamental principles in circuit analysis that describe how current and voltage behave in an electrical circuit. The first law, also known as Kirchhoff's Current Law, states that the sum of currents entering a node in a circuit is equal to the sum of currents leaving that node. The second law, Kirchhoff's Voltage Law, states that the sum of voltage drops around a closed loop in a circuit is equal to the sum of voltage rises. These laws are important for understanding and analyzing complex electrical circuits.

How do Kirchhoff's Laws apply to real-life situations?

Kirchhoff's Laws can be applied to real-life situations in many ways, such as in the design and analysis of electrical circuits in buildings, electronic devices, and power systems. They are also used in industries such as telecommunications, transportation, and manufacturing to ensure the proper functioning and safety of electrical systems.

Can Kirchhoff's Laws be violated?

No, Kirchhoff's Laws are fundamental laws of physics and cannot be violated. However, in certain situations, such as in non-linear or time-varying circuits, they may not apply directly. In these cases, more advanced principles and techniques must be used to analyze the circuit.

How can I apply Kirchhoff's Laws to solve circuit problems?

To apply Kirchhoff's Laws to solve circuit problems, follow these steps: 1) Draw a circuit diagram, 2) Label all components and their values, 3) Identify nodes and loops in the circuit, 4) Apply Kirchhoff's Laws to write equations for each node and loop, 5) Solve the equations to find the unknown values, and 6) Check your solution by using the equations to verify that they are satisfied. Practice and familiarity with circuit analysis techniques will also help in effectively applying Kirchhoff's Laws.

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