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  1. M

    Differences in the Brightness of bulbs for 2 separate circuits

    I came across 2 similar example problems while studying for my exam and I want to make sure I get the differences between the two before I take my test later this evening. (This might be long but I have an exam coming up and I don't want to go into it with any uncertainties. I appreciate anyone...
  2. M

    Find unknown values of current in multi-loop circuit

    Thank you SO much for clearing that up, honestly. I spent hours trying to figure out how it could be correct. That final equation for the right loop is what was confusing me. Her initial equation for the right loop is : -i2R2 + V2 - i3R3 and the sign of the V2 is what was confusing me. It...
  3. M

    Find unknown values of current in multi-loop circuit

    So I'm going over my review questions/notes provided by my professor for the upcoming exam on Tuesday, and I came across an example problem that I THINK might be a typo, but I want to make sure I'm right. I'm not sure why the potential drop when crossing V2 is ADDED to the loop equation for...
  4. M

    Find the maximum potential difference across a series circuit

    Hey, hope you’re still with me. I’ve been dealing with a cold so I got some early sleep yesterday. I know the charge on each of the plates can’t be any greater than 1.25e-3 because capacitor C1 has a capacitance of 10.0e-6. Dividing this from Q will give us 125V ( V = Q/C) for that capacitor...
  5. M

    Find the maximum potential difference across a series circuit

    That all the capacitors in the series will have the same magnitude charge on each of their plates. So initially, they will all have zero charge, and then will have charge Q on each plate. (+Q and -Q)
  6. M

    Find the maximum potential difference across a series circuit

    Yeah sorry about that. The online HW site im using (Webassign) has a reputation around here of being notoriously terrible with the questions they ask, so thanks for sticking with me still. Well, to start, I guess If the max V that any single capacitor here can have is 125V, that must mean the...
  7. M

    Find the maximum potential difference across a series circuit

    From your previous response, if the maximum V that any of the 3 capacitors can have in this circuit is 125V, and this is a series, then the sum of the voltages across each capacitor will add up to the total supply voltage of the circuit? That would mean 125 * 3 = 375V for the maximum voltage...
  8. M

    Find the maximum potential difference across a series circuit

    I'm somewhat familiar with Kirchhoff's rules but only because I just googled it. This question came from an online HW platform and each set of questions are based off a specific chapter. In this case, its chapter 8 (capacitors) for me. Kirchhoff's rules aren't discussed until chapter 10, so this...
  9. M

    Find the maximum potential difference across a series circuit

    I'm not really sure what I need to find exactly. From what I'm seeing, I could give C1 the max potential difference of 125V because it has the lowest capacitance, and because V = Q/C, this means the capacitor with the highest potential difference across its plates will be the one with the lowest...
  10. M

    Find the charge on the plates of a parallel-plate capacitor w/ dielectric

    Yes, I think I see what you mean. I did get the correct answer (2.1e-7), but I want to make sure I know why I got the wrong answer at first So excluding the fact that we have a dielectric : C = ε0 * (a/d) = 7.72e-14 V = E*D = 893750 J/C Now solve for Q, where Q = C*V, but enter the...
  11. M

    Find the charge on the plates of a parallel-plate capacitor w/ dielectric

    This is an online HW question so maybe my digits are just off from rounding or something, but I don't know why I am not finding the correct answer. I got Q = 6.9e-8 as the magnitude of charge on each plate. I basically just needed to calculate the original capacitance of this capacitor using c...
  12. M

    I Prove to me how capacitors in parallel can have the same V across plates

    Ok, let me see if I've got this correct. So, E ∝ Q. However, Q doesn't reach the plates without the V from the battery moving it. So I can see how the poster before you is correct by saying that the E field depends on the V, not the other way around. So, basically, this is saying E ∝ V. If you...
  13. M

    I Prove to me how capacitors in parallel can have the same V across plates

    The only way I can kind of see how it makes sense is if you use V = Q/C and plug in Q*d/ε0*a for V. Then you get: Q*D/ε0*a = Q/C. Then, the charge Q cancels so V wont depend on the electric field or the charge Q on the capacitor plates.....but this just goes against everything I learned...
  14. M

    I Prove to me how capacitors in parallel can have the same V across plates

    *If at any point I say something incorrect or its clear I don't have the right understanding of something, please point it out and correct me. I need to be sure I'm understanding it all correctly. So please don't answer unless you're willing to read this entire post* So I know capacitors in...
  15. M

    Find the E-Field between plates when given only given part of the total voltage

    Lmao I really hope so.... So basically the electric potential difference does not depend on the charge moving withing the field between the plates. It only depends on the distance between two separate points within the electric field. So basically, its the electric potential energy difference...
  16. M

    Find the E-Field between plates when given only given part of the total voltage

    Yes. Its making sense now. So JUST the potential is like saying " here is a charge at (x1) distance from the origin. This has a potential of V = E*x1. Potential DIFFERENCE is " here is the same charge that was at (x1) distance from the origin. Now I move this charge to a distance (x2) from the...
  17. M

    Find the E-Field between plates when given only given part of the total voltage

    Ok, ok. I think I've got it now: So when calculating the E field here, we can use the given voltage of 693v in the equation even though that isn't the total voltage between the actual distance between the plates (10cm) because the electric field will remain constant between these plates. and...
  18. M

    Find the E-Field between plates when given only given part of the total voltage

    Yes, E = 693V/.0785m However, this just doesn't make any sense to me. Sorry if I'm being annoying but I don't want to just be satisfied getting the correct answer without seeing how it makes sense. This figure in my textbook is what is confusing me: So, if these were the plates in my...
  19. M

    Find the E-Field between plates when given only given part of the total voltage

    Good morning. I think I understand now but I want to make sure ...(getting the right answer without understanding isn't going to help me) So, in this case we have the plates at 10 cm apart. So when they say that the potential difference at 7.85 cm away from the zero volt plate is 693v, that is...
  20. M

    Find the E-Field between plates when given only given part of the total voltage

    I don't think this is the answer you're looking for but it's the only thing I can think of at the moment: That V = E*D so the potential difference would also be constant (as long as the distance stays the same)? If that's the case though, then that would mean I could still use E=V/D with my V...
  21. M

    Find the E-Field between plates when given only given part of the total voltage

    Assuming that they both have same magnitude charge and opposite signs, then the electric field will be uniform; extending from the positive plate to the negative plate.
  22. M

    Find the E-Field between plates when given only given part of the total voltage

    I'm really unsure about how to solve this because I am not given the total voltage between the plates. The voltage given (693V) is at a point that is 7.85 cm away from the zero volt plate. If I was given the total voltage between the complete distance between the plates (10 cm), then I could...
  23. M

    Net charge contained by a cube in a region with a non-uniform E field

    I'm still confused for 2 reasons: 1. the field along the y and z axis in my problem IS uniform (from what I was told by my T.A.) because it doesn't depend on where you are along the y or z axis; whereas the field along the x axis is not uniform because it depends on the distance "x". 2. From...
  24. M

    Net charge contained by a cube in a region with a non-uniform E field

    I'm having a little trouble understanding how to go about solving this problem. I was in class Tuesday and the hint I got from the T.A. running my discussion section was that : "because the electric field is only non-uniform along the x axis, the electric field will both enter(negative flux) and...
  25. M

    Calculate linear charge density of rod & mag. of E-field at point

    Thanks for the quick response! Yes, I get what you mean by having the dq and dr terms in the integral. I shouldn't have expressed it like that. Also, I do have a bad habit with writing down everything as I'm working through a problem. I assuming the main advantage of not plugging in numbers...
  26. M

    Calculate linear charge density of rod & mag. of E-field at point

    Here is my work done for this problem, along with a diagram of the situation. I'm not worried so much about the arithmetic because our tests are only 50 min long so the problems they give us do not require heavy integration or calculus, but you need to know what goes where in the formula. That...
  27. M

    Question on Calculating Coulomb force in VECTOR FORM

    Lmao. You're right. My signs of the components of the force vector were backwards. Q2 will attract Q1 so Q1 will accelerate in both the POSITIVE x and y directions. I had both components of the force vector as negative. I switched the signs and got the correct answer on Webassign. I spent like...
  28. M

    Question on Calculating Coulomb force in VECTOR FORM

    The only thing tripping me up here is that the answer needs to be in vector form. If the question was asking for the scalar form, then I would just find the distance between the charges (plot the charges according to their vector coordinates, then use pythagorean theorem to find the distance...
  29. M

    B Question about the polarity of a voltage (PHY 2 for engineers)

    You are correct. I did not accurately quote my textbook. This was the case of a CIRCUIT connected to a battery moving a NEGATIVE charge from its negative terminal to its positive terminal (the circuit was a headlamp). So, if I truly do understand this time, the voltage is the potential...
  30. M

    B Question about the polarity of a voltage (PHY 2 for engineers)

    My problem is understanding how the polarity of a voltage makes sense. For example, In my textbook, its states that "batteries move negative charges from its negative terminal to its positive terminal. In terms of potential, the positive terminal is at a HIGHER voltage than the negative...
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