voltage

  1. G

    Molecules With Radio Emission Under Current

    I am working on a project, however I am having trouble finding the right material for it to work. I am looking for a nano-material or any molecule that will emit a radio frequency when subjected to a voltage or a current at around 37 degrees Celsius. I would really appreciate it if someone could...
  2. Dikshant

    Confusing relation between power,volatage and current

    Hii,i'm new in electrical and much confused bcoz of complicated relation between V,I, nd P. If P = VI = cons. and increasing V,decrease the value of I, but since P is also equal to I×I ×R and r is cons.,so decrease in I will always cause P to decrease which is supposed to remain constant. And i...
  3. AdityaDev

    DC power supply

    How do i get 250v dc power supply?? Should I use lots of batteries or is there an easier way?
  4. N

    Lightbulb I/V curve question

    The question I've been given this question by a teacher and I'm clueless as to what b) and c) are. Could you please help? I would really appreciate it. The prize is a place to see a lecture on quantum simulation at our local University. Thank you :)
  5. U

    Domestic Water Pump (1 HP)

    Hi there, I have spent quite some time on PF as an unregistered user reading through various stuff and have learned a lot. Just registered now to seek help on something that's been bothering me a lot and to which I haven't managed to find a solution yet. Please let me know if this is not the...
  6. SalfordPhysics

    Helmholtz Resonator using voltmeter

    Hi, I am trying to understand how precisely a voltmeter is used to measure the resonant frequency of a sound wave in a helmholtz resonator. Is it simply that the maximum voltage corresponds to the resonant frequency? A detailed description or external link would be great. Many thanks.
  7. C

    Power dissipation limit for a resistor

    I am confused about the concept of a power dissipation limit for a resistor. Basically for a resistor the product of the current through it and the potential across it should not exceed 0.25 watt otherwise it starts to heat up and act in a non-linear fashion. Is this value just a constant or is...
  8. G

    Finding Unknown Currents in a Two-battery Complex Circuit

    1. Homework Statement Look at the circuit given in figure 1. Solve for the three currents, I1,I2,I3. 2. Homework Equations KVL: Sum of voltages in a closed loop equals zero KCL: Sum of currents entering a junction equals the sum of currents exiting a junction Ohm's Law: V=IR NOTE: Nodal...
  9. M

    Find the resistance for maximum power transfer

    1. Homework Statement Find the value of R where RL equals 50 Ω, for maximum power transfer I= 2A, R_L=50 ohms 2. Homework Equations R_th=V_oc/I_sc KCL,KVL,V=IR 3. The Attempt at a Solution First, I created an open circuit including everything except R_L. Then i tried to solve for the Open...
  10. T

    Voltage transformers and magnetic field leakage

    I’m looking to purchase a toroidal AUSTRALIA-to-US stepdown voltage transformer, and have narrowed my choice down to two models, one permitting a maximum rate of energy consumption of 100 Watts, and the other permitting a maximum rate of energy consumption of 250 Watts. Both of these maximum...
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