Voltage drop Definition and 201 Threads

  1. D

    Resistor currect and voltage drop in a circuit.

    Consider this circuit with R1 = 30 ohm, R2 = 10 ohm, R3 = 10 ohm, R4 = 20 ohm, R5 = 60 ohm. (the circuit is attached) A. What is the current across the resistor R2, if a voltage of 110 Volt is applied to the two terminals at the bottom of the figure? B. What is the voltage drop across R2...
  2. U

    Voltage Drop and Power: Exploring the Difference

    Just curious: is the voltage drop across a load an expression of how much energy that device uses? If it is, what is the difference between voltage drop and power? Power is also used to determine the energy usage of a device, right? These aren't very important questions. I've just been...
  3. X

    Confused: potential difference vs. voltage drop?

    Homework Statement In Fig. 28-5a calculate the potential difference across R2, assuming = 14 V, R1 = 6.0 , R2 = 3.0 , and R3 = 2.0. (image isn't working online, but it's a simple circuit- all the resistors are in series) Homework Equations V = IR The Attempt at a Solution Req...
  4. R

    NPN 2N3904 Transistor Voltage Drop

    Does anybody happen to know what it is, or how to find out the voltage drop of a particular transistor?
  5. B

    Voltage drop calculation in 3 phase unbalance circuit

    Dear All, I’m facing some problem when I try to determine the total voltage drop (%) from the source to the load. Assume the condition as follow: 1. DB-A is serving 3 number of individual load (#1,#2 and #3) , each 100m away from DB-A, single phase, 5kw, pf=0.85, V=240V,by using...
  6. R

    Solving Voltage Drop Problem on Robotics Project

    22 Dec 2009 21:16 Voltage drop question Hi All; Total noob, first post:smile: I'm working on a small robotics project. I have an embedded computer (5V) and 2 motors with a controller. It's all powered from a 4.8V NIMH battery. The problem I'm having; As the battery gets...
  7. S

    Transmission Line, voltage drop

    Homework Statement Prove that for a line having resistance R, and reactance X, and supplying load of P+jQ has an approximate voltage drop of: Vr = [RP+XQ]/Vs Homework Equations none given. The Attempt at a Solution I made a diagram, with R, X, and P+jQ in series. Vr is the...
  8. S

    Voltage Drop: Source A to B in a Circuit?

    Is voltage the potential energy difference between source A and B in a circuit? If so in absense of resistance and the presence of a 3V battery does point A have 3V to begin with and at point B there is 0 volts. Is all potential energy converted to kinetic energy when moving from A to B? A is...
  9. S

    Voltage Drop in Diode: Exploring Causes & Amplifier Doubts

    the depletion region is resposible for voltage drop all that is fine but in forward bias there is no depletion region hence there can be no voltage drop but it is mentioned in my book that the voltage will drop by .7 volt how come this can happen also i have many doubts in transistor...
  10. R

    Fluctuating voltage drop in radio

    Hi Experts :!), I tried to use a 5v dc voltage source to power a normal handheld 3v radio using a resistor to regulate the voltage. The voltage drop across the resistor seems to fluctuate constantly by about +/- 0.8 volts. So, the voltage drop across the resistor fluctuates between 1.5v...
  11. U

    What is the difference between voltage drop and wattage?

    Voltage drop is how much energy a device uses. Wattage is the rate of energy transferred into the device per unit of time. Aren't both essentially the same thing? Or am I just confused?
  12. J

    Calculating Voltage Drop in an AC circuit

    Homework Statement I have a couple of questions about one of my homework assignments any help would be greatly appreciated. 1. How do you find the Voltage drop of a Resistor in an AC Circuit is it similar to DC? V=IR The Resitor value is 68 ohms and there is an 80mH inductor in front of...
  13. T

    Voltage Drop across multiple resistors

    Homework Statement Solve for all unkown i's and V's EDIT: there is a seventh resistor that is right under the negative side of the source. Vs=12V Homework Equations V=IR The Attempt at a Solution I got the I's by finding the voltage across the entire 2 loops to equal 0, then...
  14. T

    Understanding resistors and voltage drop

    Homework Statement Determine Req, the missing I's and V's? Homework Equations V=IR The Attempt at a Solution First problem is that I thought I learned that R2 and R3 are in parallel so you have to use the recipercal rule, but looking back at my notes for Interpetation...
  15. C

    RLC Circuit - Voltage drop across Inductor

    Homework Statement A 10 μF capacitor and a 25 H inductor are connected in series with a 60 Hz source whose rms output is 112 V. Find the voltage drop across the inductor. Answer in units of V. Note: Sigfigs do not matter Homework Equations I = V/Z where Z is the impedence XL =...
  16. V

    Difference between voltage and voltage drop?

    Homework Statement A power station delivers 440 kW of power through 3 ohm lines. How much power is wasted if it is delievered at 12000v? Homework Equations v=IR P=I^2R P=IV The Attempt at a Solution I believe you are supposed to solve it like this but I do not understand why...
  17. M

    Calculating voltage drop across diodes

    Hey guys I am completely new to this site and electronics so forgive me. I've uploaded a photo of the question. I am trying to work out at what values does just D1 conduct D1 and D2 conduct then finally all of them. Im really stuck here. i know that the diodes start conducting when the...
  18. N

    What is the voltage drop across a diode when it is reverse biased?

    Hi guys, I have a very simple question but which is messing with my mind. I'm trying to figure out the voltage drop across a diode when it is reverse biased, and I'm just not getting anywhere. Can someone please take a look at the attached image and explain to me what the voltage drop across...
  19. Z

    How Do You Calculate Voltage Drop in a Copper Wire?

    Compute the voltage drop along a 25 m length of household no. 14 copper wire (used in 15A circuits). The wire has diameter 1.628 mm and carries a 15 A current. Vdrop=I*R R=rho(L/A) I just plugged the resistivity of copper wire which is 1.72*10^-8, length, and area into find the...
  20. K

    Voltage drop in Capacitors and Lightbulbs

    The batteries in this cicuit create a total voltage difference of 6 volts across the circuit. Assume A is 6 vols in each circuit, Record the voltage of the lettered locations at the time when the circuit is first connected, and later when it is fully charged Note: bulbs below are identical...
  21. chevywaldo

    Voltage Drop Question - Building Wiring

    I'm not understanding something very basic here. I know what voltage drop is. At least I thought I did. Here is a question: Assume you have a power supply in a control panel of a building. 500 feet away is the load device. When doing voltage drop calculations for the wire (500 feet...
  22. Z

    Voltage drop across a capacitor

    Homework Statement The left plate of a parallel plate capacitor carries a positive charge Q, and the right plate carries a negative charge -Q. The magnitude of the electric field between the plates is 100 kV/m. The plates each have an area of 2 × 10-3 m2, and the spacing between the plates...
  23. L

    Why Multiply by sqrt(3) in Voltage Drop Formula?

    I have a 45kW VSD drive with pf of .9 and FL amp of 75A, I have a 350m run from the MCC to the VSD itself and I'm trying to calculate what size cable I need so that I don't exceed the specified voltage drop of 3%. The line-line voltage where the motor is to be placed is 400V and the cable...
  24. X

    Help Voltage drop is driving me insane

    Help! Voltage drop is driving me insane! 1. If the Voltage Drop across a load increases due to its added resistance, what happens to the voltage drop across other segments on the circuit? 2 Why does resistance decrease Voltage (create voltage drop) if the Voltage is a Force "APPLIED" to the...
  25. S

    How Can I Accurately Measure Voltage Drop across a Capacitor?

    Hi all, Here's the problem! I am attempting to create a leakage current test suite. Basically it centers around cutting the voltage reference supply to a capacitor and measuring the voltage drop. Similar to the one in the attachment. I figured that to determine the drop it would be a...
  26. L

    How Does Cable Size Affect Voltage Drop in Three-Phase Systems?

    I was just looking for some insight on this problem. It is not a homework problem, my boss just asked me to figure it out. Now, there is 120V supply, with 600 feet of cable (copper) running to a load, and 600 ft neutral coming back to the supply. Ignoring the resistance of the load, he asked...
  27. I

    Calculating Voltage Drop in a 6V Circuit with 18 Gauge Copper Wire

    Im going to college first year in sept for Mechtronics and I am reading in advance for electricity which i know is guna give me problems. Right now I am stuck on this question. Dont tell me the answer but rather how if find it. 27) A 6V source is connected to a 100 ohm resistor by two 12...
  28. F

    Why must voltage drop across a resistive circuit?

    Hi, I am having difficulty understanding why potential must drop completely over a circuit from the high side of the source to the low side of the source. I've seen this statement in several books now with no further explanation other than "it must". Consider a simple dc circuit consisting of...
  29. L

    Help Sawmill application: Voltage drop.

    Before I go too indepth, I wanted to make sure this was the proper place to post this. I stated in my intro I am doing a co-op work experience. I am working at a sawmill, and I have been asked to look at a few situations and things like that around the mill. I have been here for a couple weeks...
  30. M

    Checking Voltage Drop while Supplying 6A Current

    Homework Statement You would like to check if the battery voltage drops while it is supplying a current of 6A. You use a voltmeter designed to measure voltages up to 20V and having a resistance of 50,000 Ohms. See attachment**** This connection is in series so V= I (R1+R2) V / (R1+R2) =...
  31. S

    Voltage Drop & RE in NPN Transistors

    Is the voltage drop across the emitter in an NPN transistor equal to 0? What is the purpose of RE (found immediately after the emitter?)
  32. A

    Voltage drop across a capacitor

    Homework Statement Below, I have attached a schematic that was on a test question for me. (NOTE: R4 = 4*r) We were supposed to find the current leaving the battery in terms of R, C, and Vb. The thing was, I had no idea what the voltage drop across the capacitor would be since there is no q...
  33. R

    Effects of Voltage Drop on a Refrigerator Rated 80W & 250V

    Homework Statement A refrigerator is marked 80W and 250 V. What is likely to happen if the voltage falls to 50V? Homework Equations P=V^2/R V=IR The Attempt at a Solution --------------------------------------------------------- R=V^2/P =250*250/80 =781.25 ohm Assuming the...
  34. M

    How Can I Minimize Voltage Drop Across a 50 ft Wire with 80A Load?

    Hi all, I'd like to ask for your help in solving a problem. I'm currently working on building a small ground robot for a certain research problem. The robot is powered by batteries, and consumes a continuous 80A @ 12V when all of its systems are active. The batteries provide capacity for...
  35. M

    Engineering Voltage drop across a capacitor in a circuit

    Find the voltage drop across the capacitor In a circuit where a voltage source is connected to a capacitor and resistor in series and then connected to another resistor, shouldn't the current going through the capacitor be 0ma after 5 time constants, resulting in a Vc being 0?
  36. L

    Voltage Drop Across Indicator Lamp

    Hi, I am new here so please bare with me. I know a bit about electrical and Electronics but I do not recall the formula for this application...it is a long question..please help! Here it is. Six cells are connected in series to form a battery. Each cell has a rating of 1.5 volts and 1 amp...
  37. M

    Series circuit lab problem: voltage drop?

    Hi, I am having a problem with my lab report and am hoping somebody can help me understand it better. Here is my problem: I set up a series circuit with 5 resistors of 427 ohms each. The voltage of the battery was 8.70V to start. Once the battery was removed from the circuit its...
  38. J

    Voltage Drop Across Transmission Lines

    Homework Statement A pair of power transmission lines each have a 0.850 Ω resistance and carry 779 A over 9.85 km. If the rms input voltage is 39.5 kV, calculate the voltage at the other end. Homework Equations The Attempt at a Solution
  39. M

    Calculating Voltage Drop Across 5kOhm Resistor

    Homework Statement A 6V DC voltage source is connected across both a 5kohm resistor and a 10 nF capacitor in series. The voltage drop across the resistor is what? Reply With Quote Homework Equations Q=CV The Attempt at a Solution Q= (10*10^-9 F)(5000ohms)
  40. S

    Conceptual Question about Resistance and Voltage Drop

    Hi, 1) Can anyone explain to me from a conceptual standpoint, why increased current leads to an increased voltage drop across a resistor? Mathematically, I know V=IR. But it doesn't make sense to me why increasing a current across a resistor would lead to a greater drop in energy per...
  41. D

    OR Gate Voltage Drop: A=5V, B=4.6V

    Hi! I've got another diode OR gate problem. When the voltage at the input A is 5V and it's 4.6V at the input B, does the output voltage still remain at 4.4V? Does it mean that the D2 diode is forward biased and its voltage drop* is smaller than the voltage drop of the D1 diode? *the...
  42. D

    Choosing Resistors for Diode AND and OR Gates

    Hi! There's a schema of a diode AND gate attached. Could anyone of you, please, explain me why the voltage drop across the D1 diode is so big compared to the voltage drop across the D2 diode? Thanks a lot in advance!
  43. R

    My LED: Connecting Diodes for Voltage Drop

    Hi, this is my diode: http://img201.imageshack.us/img201/2862/untitledmq1.png Ok, I know Vcathode < Vanode in order for the LED to light up through the current sent through it. Now, my question is, if the three Diodes are connected to 0v, Vanode > Vcathode, therefore the LED will light...
  44. P

    How to Calculate Voltage Drop in a Circuit

    Hello Everyone, I am a High school student who would like for some of the senior members to take look at some of my workings and maybe help me out when I run into trouble. I am presently out of school for the summer, 2 more years of high school, left where I hop to go to University to become...
  45. V

    Calculating Voltage Drop for 200HP Motor at 480V

    Hi, I was wondering if anyone can help me figure out how much voltage drop is happening in this particular scenario. Here is my work: Given 200HP motor at 480V that is 300 ft. away from the starter. %VD(3phase) = [12(1.73)(300ft.)(240A)]/[(Circular mil) * (480V)] x100 I use 12 for...
  46. M

    Confused on concept of finding voltage drop across a resistor

    Hello everyone I have a slight problem. I am confused on how you know what path current is going to travel and also what voltage sources your suppose to add up to a specific resistor. For example here is my picture, already solved: The directions where to find the value of ix, the orignal...
  47. A

    LED Voltage Drop Fluctuation: Investigating the Cause

    hi i have fixed a simple circuit for lighting up a led.i have included a potentiometer. as the led is white i know that the voltage drop of the led is around 4v.when the potentiometer is at min resistance the voltege drop is actuallu around 3.8v.the problem is that when i turn the potentiometer...
  48. C

    Finding voltage drop in parallel and series circuits

    i think i may have the solution to this problem, but something about it is still bothering me. the question is, if you have a 100W and a 60W bulb, both on the same series circuit, across which bulb will there be a greater voltage drop? if the same are on a parallel circuit?.. as i...
  49. C

    Very low voltage drop transistor

    I'd like to construct a fast-reacting current overload protection device. And rather than use a FET as a short to blow a fuse I'd rather just use a semiconductor in series that I can open on overload. This is similar in operation to some "intelligent circuit breakers" based on a Intra...
  50. P

    Voltage Drop in Circuits with Parallel Components

    When a volt meter is placed in a circuit on its own the reading is say 4v. But when a component, 'x', is placed in parallel the voltage drops. Why is this?? Physman
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