Circuit Lab B/C

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azboy1910
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Re: Circuit Lab B/C

Post by azboy1910 »

I wanted to make this post to apologize for my misleading post from before. I did not know "+" actually mean "or," and I apologize if I confused anyone before. I'll keep in mind next time to make sure to have a good understanding of the topic before I try to post a response to any event related question by the community.
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Re: Circuit Lab B/C

Post by RiverWalker88 »

azboy1910 wrote: October 2nd, 2020, 12:59 pm I wanted to make this post to apologize for my misleading post from before. I did not know "+" actually mean "or," and I apologize if I confused anyone before. I'll keep in mind next time to make sure to have a good understanding of the topic before I try to post a response to any event related question by the community.
No worries! We all make mistakes, and sometimes can unintentionally give inaccurate information. The purpose of the forums is to increase everyone's understanding, so, even though your initial answer may not have been fully correct, it gave another opportunity for us to gain a better understanding. Nobody faults you for trying to be helpful--rather we appreciate your engagement.

And on another note (to add to this discussion), there is another boolean logic operation, XOR (⊕) that means that the output will only be true if exactly one input is true, but not both.

Truth table:

Code: Select all

INPUT A | INPUT B | OUTPUT
   0    |    0    |   0
   0    |    1    |   1
   1    |    0    |   1
   1    |    1    |   0
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Re: Circuit Lab B/C

Post by jaggie34 »

Check out the analysis for the GGSO circuit test here
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and Circuit Lab too I guess
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Re: Circuit Lab B/C

Post by njain110706 »

How does one get good at circuit analysis easily? I seem to be struggling every single time I take practice tests, and I've even watched most of Organic Chemistry Tutor's videos on the analysis methods but I still am not getting any progress with my analysis skills.
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Re: Circuit Lab B/C

Post by azboy1910 »

njain110706 wrote: March 15th, 2021, 7:06 am How does one get good at circuit analysis easily? I seem to be struggling every single time I take practice tests, and I've even watched most of Organic Chemistry Tutor's videos on the analysis methods but I still am not getting any progress with my analysis skills.
Getting better at circuit analysis is mainly just practice. You most likely won't get the hang of it just after solving one circuit. I will say though that it is helpful to know some basic information, which you can use in circuit analysis. This includes the following:
  • Knowing how to use Ohm's Law.
  • Basic knowledge of series and parallel resistors, such as that series resistors share the same current and just identifying them in general.
  • Knowing Kirchhoff's Circuit Laws and knowing how to apply them in circuit analysis.
I think it would be helpful if someone explained step-by-step though how to solve a circuit in a way that you can understand for circuits you are stuck on, I believe that would be helpful. If you need me to explain it even, just PM me and I'll do my best to try and explain! I hope you've had a great day and I hope this helped out a bit!
Last edited by azboy1910 on March 15th, 2021, 1:20 pm, edited 2 times in total.
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Switch and lamp problem

Post by ss25science »

Hi everyone,
I had a question with the following problem. The answer key gave me the answer but I am not sure how they got it. Please explain.

Four identical incandescent light bulbs L1, L2, L3, L4, and a battery are connected as shown on the diagram on the right. The three switches S1, S2, S3 are open. How will the
brightness of the four lamps change compared to the original state if the specified switches are closed (all other switches are open)?
Example: S1 closed. Expected Answer: L1 - off, L2 - same, L3 - brighter, L4 - brighter.
Answer the following scenario: A) S2 closed; (B) S3 closed; (C) S1 and S2 closed; (D) S2 and S3 closed.

Answer: A) Answer: L1 - brighter, L2 - same, L3 - off, L4 - off B) Answer: L1 - off, L2 - same, L3 - off, L4 - brighter C) Answer: all lamps off (short circuit) D) Answer: L1 -
brighter, L2 - same, L3 - brighter

Thank you so much!
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Here is the given circuit
Here is the given circuit
Capture switch.JPG (12.01 KiB) Viewed 2880 times
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Re: Switch and lamp problem

Post by azboy1910 »

ss25science wrote: April 4th, 2021, 2:11 pm Hi everyone,
I had a question with the following problem. The answer key gave me the answer but I am not sure how they got it. Please explain.

Four identical incandescent light bulbs L1, L2, L3, L4, and a battery are connected as shown on the diagram on the right. The three switches S1, S2, S3 are open. How will the
brightness of the four lamps change compared to the original state if the specified switches are closed (all other switches are open)?
Example: S1 closed. Expected Answer: L1 - off, L2 - same, L3 - brighter, L4 - brighter.
Answer the following scenario: A) S2 closed; (B) S3 closed; (C) S1 and S2 closed; (D) S2 and S3 closed.

Answer: A) Answer: L1 - brighter, L2 - same, L3 - off, L4 - off B) Answer: L1 - off, L2 - same, L3 - off, L4 - brighter C) Answer: all lamps off (short circuit) D) Answer: L1 -
brighter, L2 - same, L3 - brighter

Thank you so much!
Hey,

To answer your question, you need to analyze the circuit before any switches are closed because the circuit in this state is our point of comparison used in this problem. When no switches are closed, current flows through all the lamps, but the most through L2 because it’s in parallel with the battery, so it’s supplied the same voltage as the battery. The other 3 lamps split the voltage because while that entire branch is in parallel with L2, which is in parallel with the battery, the branch containing the three lamps would have three times as less current because the branches combined resistance (if you added up the resistance of lamps 1, 3 and 4) is three times of that of L2. This means that the power that determines the brightness of the lamps is 3 times greater for L2 than it is for L1, L3 and L4.

Part (a)
After S2 is closed, the brightness of L2 does not change because it’s still in parallel with the battery, so it has the same voltage and therefore the same power. L1 increases in brightness because more power is delivered to L1 because L3 and L4 are shorted, meaning there’s less resistance and more current in the branch where L1 is located, resulting and more power being delivered to that branch. L3 and L4 are shorted by the wire containing S2.

Part (b)
When S3 is closed, L2 would be the same (see part a). L1 and L3 are both shorted by the wire containing S3, causing L4 to be brighter for the same reason that L1 in part A increased in brightness.

Part (c)
When S1 and S2 are both closed, the wire containing S1 shorts both L1 and L2, while the wire containing S2 shorts both L3 and L4. For this reason, all the bulbs are off.

Part (d)
When S2 and S3 are both closed, the wires containing S2 and S3 short L3, but the the brightness of L1 and L4 increase because there’s less resistance in that branch. L2 is the same because nothing has changed, it’s still in parallel with the battery. I’m not sure exactly how L3 is increasing in brightness according to them, but I could’ve also gone wrong somewhere.

I apologize for the poor explanations, but if anything is confusing for you, please feel free to reach out to me about it. I’m not sure how much sense this actually made, but I hoped it helped you at least a little bit :)
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Re: Circuit Lab B/C

Post by sciolyperson1 »

Hi all!

We're running Circuit Lab for this month's SMEC! To learn more, head over to our forums thread and register at the google form here!
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