1. J

    Energy of band of d-dimensional semiconductor when voltage V is applied across

    Let's say we have a one-dimensional semiconductor and I apply voltage V across it, I want to calculate the energy of a parabolic band, when a source and drain voltage is applied across it. I expect it to be $U = \Sigma_k \frac{\hbar^2 k^2}{2 m^*}f(k)$ where f(k) is the fermi function. When no...
  2. A

    How to calculate thevenin's voltage?

    How do i calculate the potential difference between Va and Vb?
  3. M

    [ASK] Voltage and Current

    An AC current has 100 V voltage. An electric iron with 20 Ω resistance is connected to the current source. Determine effective value, maximum value, and average value of: a. the voltage b. electric current How do I do this without knowing the value of sinωt? At least please help me to find...
  4. H

    Voltage & Current & Push & Force & Potential

    I’m trying to understand what voltage is. Getting confused. (i) Is voltage a FORCE that can give PUSH to coulombs to make them flow in a wire. That force is found in the power source e.g. battery? (ii) Is it a measure of how much energy can be transferred per coulomb to, say a light bulb...
  5. H

    Voltage and current confusion. Please check my understanding of it

    Hello, I’m confused about current and voltage. My understanding is fragile and I need to reinforce it with your help. Below I’ve written what I think I know to be correct. Please correct me where required. This is high school physics. (i) Current is the rate of flow of electrical charge...
  6. C

    Voltage Drop Across Electrodes

    Hello, I am a chemist running an electrochemical cell, and I am hoping for some pointers on how to calculate the voltage drop across electrodes as a function of position. The simplest embodiment of the cell consists of a rectangular sheet electrode surrounded by a second wire electrode...
  7. N

    Harmonic voltage

    How does the load react when applied the harmonic voltage? Is there more than one harmonic voltage? How do we use it when we want to calculate the average power of a load? Thank you for your help.
  8. R

    Help needed: 1. Detecting Phase sequence with light bulbs/ 2. Short circuit voltage

    Hello, (Three-phase electric power) 1) If one is using light bulbs to detect phase sequence then it is wise to connect them in series with circuit/scheme resistor. Why ? Because otherwise light bulbs would have same brightness ? But why (if it is even right lead). 2) There is...
  9. H

    AC voltage

    Hi, I have a problem regarding voltage. I am beginner at these and do not know where to start this question. Can someone help me with it? The question is attached here : Thanks a lot for your time.
  10. N

    battery voltage

    what do you mean by 'a battery of 6 volts' I am confused does it mean that the battery can tranfer 6 coulomb of charge by spending 1 joule of energy per coulomb ? and what about the time it takes to transfer the charge? Please help
  11. I

    Voltage across points in a series circuit

    As the subject suggests, I'm trying to solve voltages in a series circuit. These voltages do not correlate to a component, but rather the voltage of points in between the components. I've made a picture to illustrate what I'm talking about: Now if I use KVL, for V1 I get -10V, V2 I get...
  12. R

    Voltage in this circuit?

    I have a generator that produces 0,5 Watt. This generator is connected to a voltage regulator which outputs a constant voltage of 5V. Does that mean that both the current and the voltage is constant, since the generator always delivers 0,5 Watt? To simply my circuit, the generator is my voltage...
  13. T

    Voltage in a circuit

    Hello this is my first post here:-) I know that the voltage is the work done to get a unit of charge moving from a position to another(it's the work of the electric field) my question is across a resistance the difference of potential is the same idea? and the difference of potential is due to...
  14. F

    Voltage across a resistor

    Hi everyone. My brain has currently deserted me and i cant for the life of me think of the answer to this question. Any help would be amazing. Thanks! The voltage V(t) (in volts) across a resistor in an electrical circuit at any given time t (in seconds) is given by SQRT something to the...
  15. P

    Inductor Voltage Drop

    Why is the voltage drop in an inductor opposite to the direction of current?
  16. G

    Voltage change

    This was originally posted in MHF. But i think i don't know how to do it either.
  17. R

    capacitors in series, determine voltage.

    A 3.36uF and a 5.47uF capacitor are connected in series across a 25.0-V battery. A 7.43uF capacitor is then connected in parallel across the 3.36uF capacitor. Determine the voltage across the 7.43uF capacitor. I struggled with this problem and tried to use an equilent capacitance formula: Q =...
  18. S

    Proof of Kirchhoff's Voltage Laws

    Is there a proof for Kirchhoff's Circuit Laws using the definitions of Current and Potential Difference etc.?
  19. R

    voltage in series and parallel networks

    Hello again...I posted a couple of problems that I have attempted. I think I have a better handle on these ones, but was hoping could let me know if i am right or not. Here is what I have so far Thanks again 8.1 circuit 1: Voltage at A = 1.0V Voltage at B = .5V circuit 2: Voltage at A =...
  20. R

    voltage vs. current more than 1 battery

    Okay, last one I promise! This one is actually the one I researched a bit, but still missed lab on. Here is what I found from research (not through lab or experimenting like I normally do, I had to miss class due to unfortunate circumstances): -in parallel networks voltages stay the same...