Electric current Definition and 173 Threads

  1. M

    Boiling water using electric current

    I am very new to physics. I am searching for a way to boil water to create steam and use that steam to power a turbine and therefore create energy. I surmize that water can be boiled if enough electric current is passed through it. My question is how do I determine how much current to pass...
  2. J

    Electric Current in Special Relativity

    Consider an electric circuit at rest in the lab inertial reference frame. The circuit carries a steady electric current I. What is the current in the circuit as observed from a different inertial reference frame with a velocity of v relative to the lab frame? Thanks in advance for your answers
  3. S

    Electric current and forces problem

    Hi,im trying to work out this problem but i am slightly confused by the way in which it is phrased.It states: Three parallel wires,arranged in the form of an equilateral triangle, of side length 10cm,each carry a current of 50A in the same direction.Calculate the force on anyone wire due to...
  4. R

    Changing state from solid to liquid by application of electric current

    Hi Does there exist a material whose state it is possible to change from a solid to liquid by application of electric current? Obviously a large enough current will melt anything, but what I mean is is there some other mechanism, other than brute force heating that can cause a solid to...
  5. C

    Magnetic fields around electric current

    I have just done an experiment of magnetic fields around electric current in straight wire by using the seach coil. I have 2 questions about this... (1)why is this necessary to ensure the search coil is at the same level as the wire? My anwser:If the seach coil is not at the same level as...
  6. T

    Electric current and direct current circuits

    I seem to be having a problem getting this. I can get the first question, it is .65 A. But I can't seem to figure out the potential at point B. I used Vab = I2 * I1 but it still doesn't work.
  7. F

    Electric Current: Explaining Electron Flow

    Really basic question but... why is an electric current in the opposite direction of the flow of electrons? Doesn't make much sense to me. :confused:
  8. U

    Production of electric current

    In which of the following situations is an electric current not produced? a. a loop of wire rotates in a steady magnetic field b. a loop of wire is stationary in a steady magnetic field c. the magnetic field through the loop is increasing d. the magnetic field through the loop is decreasing...
  9. A

    Effective Resistance in Circuits: HC Verma Q&A

    Can anyone explain the concept of effective resistance between two points in a circuit. There are , on an average 6-7 resistors connected in every possible way in between the 2 points for exampe refer to H C Verma questions same for potential difference
  10. S

    Can someone explain how a magnetic field generates an electric current?

    How does a magnetic field generate an electric current? Can someone explain this to me in simple terms? Or is there a website that might help me understand this? Thanks
  11. A

    How Much Heat Does a 111V Electric Iron Develop in One Hour?

    A 111 V electric iron draws 8.9 A of current. How much heat is developed per hour? Answer in units of J. P = IV P = U/t U = IVt U = 8.9(111)(60) = 59274 J Apparently I'm wrong and I don't know why.
  12. E

    Electric current in a rotating ring

    I'm currently stuck on this question on the image attachment. Any help would be definitely ppreciated. Ok, so from what I understand, it asks what is the current that passes through the fixed line. For part (a), I see that the current is 'discontinuous', and I'm not enitrely sure how to solve...
  13. J

    Why Are My Calculations for Electrical Resistance and Current Incorrect?

    I did all the word but my answers are not matching my books? 1) Can a 2.5 mm-diameter copper wire have the same resistence as a tungsten wire of the same length? Give numerical detials. Answer, yes, 4.6 mm Here is what I did: ( p = resistivity ) R = p(L/A) so I set R(Cu) = R(tug) and...
  14. H

    Calculating Wire Current and Electron Flow: A Helpful Guide | Thank-you

    Can anyone help me with this question? Thank-you A net charge of 51 mC passes through the cross-sectional area of a wire in 10.0 s. What is the current in the wire? How many electrons pass the cross-sectional area in 1.0 min? I know that the current is .0051, but I'm having trouble finding...
  15. A

    Electric Current: Explained with Fields

    What is electric current? Let me explain my idea of it with an example of a long wire connected to the two terminals of a battery. The battery applies an electric field to the surrounding, causing a shift in the position of the electrons of the wire, especially the ones nearby. The speed and...
  16. P

    Calculating Power in AC Circuits: Solving for Minimum and Maximum Power Values

    hey guys, here's my problem... coil connected to a 240 V (rms) ac line has a resistance of 34 ohms. what is the average power used (.5)V^2 /R so Pav = 847 W then it asks what are the min and max values of the instanteous power...
  17. S

    Electric Current in a Hydrogen Atom

    This selection comes from the Serway . Beichner, Physics for Scientists and Engineers text that many undergrads are (I'm sure) familiar with! I've looked at this problem on 3 different casual occasions and on one test and still have yet to arrange the concept in my mind... "In the Bohr...
  18. J

    Why are magnetic feilds formed from an electric current?

    Why are magnetic fields formed from an electric current? and why does the field occur in an anticlockwise direction?
  19. L

    Maximizing Power Delivery: Comparing 12,000V & 50,000V Electricity Transmission

    A power station delivers 620kW of power at 12,000 V to a factory through wires with total resistance 3.0 ohms. How much less power is wasted if the electricity is delivered at 50,000V rather than 12,000V? I cannot quite picture what is going on in this problem. Is this a series circuit...
  20. E

    Electric Current - What Am I Doing Wrong?

    The equation for resisitivity is R=rho*(L/A), and the equation for current is I=V/R. So for the R equation I plugged in the numbers, changing cm to .1 m, and got 30 ohms. I then divided 110 volts by 30 and got 3.7 (rounded to two sig figs), and my answer is not being taken as correct. The...
  21. T

    Estimating cost due to power (application of electric current)

    I would like to understand this problem a bit better... A small city requires 10 MW of power. Suppose that instead of using high voltage lines to supply the power... the power is delivered at 120 V. Assuming a two wire line of 0.50 cm diameter copper wire, estimate the cost of the energy lost...
  22. L

    Chemical effect of electric current

    explain me about ionisation of copper sulphate solution when an electric current is passed through it
  23. D

    Electric current flowing in a nichrome wire

    Hiya! I have a problem that's got me confused to solve. I want to use ohms law but not right. Here is the problem. A nichrome wire has a radius 0f .5 mm and resistivity of 100 x 10^-8 ohm.m. If the wire carries a current of .5 A what is the voltage across the wire? The length of the wire is...
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