Kirchoffs Voltage Law Understanding

  • Thread starter Ryan Walkowski
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In summary, the conversation discusses the concept of Kirchhoff's voltage law and the use of arrows to depict potential changes in a circuit. The equations BE+ED+DC = +3 and BE+EF+AB = +6 are provided as examples, with the final equations being rearranged to sum to zero in order to solve for the unknown potential changes. The correct way to write the equations is also mentioned, with the starting point specified and the equation rearranged to sum to zero.
  • #1
Ryan Walkowski
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<< Mentor Note -- Thread moved as requested >>

I am trying to complete a mock paper for an upcoming assessment. The mock comes with the answers supplied in bold under the question yet I am having trouble understanding how the answers are obtained. I know that the law states that the sum of all emfs equals all the sums of the voltage drops and i have looked at several online articles but they seem to be very complex for what I need to understand. I am hoping someone can explain using the example I have. I am not sure how the arrows play a part in this either

EDIT: After much banging my head i have come up with the following.Can someone comment if this is correct and if there is a more excepted way of writing it out:

ΣV=0
B-E = -2V
E-D = +10V
D-C = -5V

BE+ED+DC = +3
∴ C-B = 3V

And

ΣV=0

B-E = -2
E-F = +8
A-B = 0

BE+EF+AB = +6
∴ F-A = 6V
IMG_6241.jpg
 
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  • #2
The arrows depict a change in potential, increasing towards the arrow head. So for example, the arrow on the battery in the left bottom corner depicts an 8 V rise in potential across the battery going from node E to node F. Similarly, on the resistor connected from E to B there's a 2 V potential increase.

Kirchhoff's voltage law states that the sum of the potential changes around a closed path is zero.
 
  • #3
Ive updated what i think is correct! If anyone can confirm
 
  • #4
Ryan Walkowski said:
Ive updated what i think is correct! If anyone can confirm
Looks okay.
 
  • #5
Ryan Walkowski said:
I know that the law states that the sum of all emfs equals all the sums of the voltage drops

gneill has already mentioned this but it's far better to think...

gneill said:
the sum of the potential changes around a closed path is zero.

and start by writing equations that sum to zero. For example you wrote..

BE+ED+DC = +3

I find I make fewer mistakes with the signs if I specify where I'm starting and write my equation to sum to zero like this..

Going anticlockwise from B..
BE + ED + DC + CB = 0

and then rearrange it to solve for the unknown CB.
 

FAQ: Kirchoffs Voltage Law Understanding

What is Kirchoff's Voltage Law (KVL)?

Kirchoff's Voltage Law is a fundamental principle in electrical circuit analysis that states that the sum of all voltages around a closed loop in a circuit is equal to zero. This means that the total voltage supplied by a source must be equal to the voltage consumed by the components in the circuit.

Why is Kirchoff's Voltage Law important?

KVL is important because it allows us to analyze complex electrical circuits and determine the voltages at different points in the circuit. It is a fundamental tool in circuit analysis and is used in many applications, including designing and troubleshooting electrical systems.

What are the key applications of Kirchoff's Voltage Law?

KVL is used in many applications, including circuit analysis, design, and troubleshooting. It is also used in the design of electronic devices, such as amplifiers, filters, and power supplies.

What are the limitations of Kirchoff's Voltage Law?

KVL is based on the assumption of ideal circuit elements, which do not exist in the real world. As a result, it may not accurately predict the behavior of circuits with non-ideal components. Additionally, KVL only applies to circuits in steady-state, meaning that it cannot be used to analyze circuits with changing voltages over time.

How can Kirchoff's Voltage Law be applied in solving circuit problems?

KVL can be applied by first identifying all the components in a circuit and then using the principle of conservation of energy to write equations for the sum of voltages around a closed loop in the circuit. These equations can then be solved to determine the unknown voltages in the circuit.

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