Electricity Definition and 999 Threads

  1. S

    Resistors in Series - Lab data confusion

    Hi guys! (see my attached photo to better understand where I am coming from!) So after some research, I've discovered that the current at different points in a simple series circuit is supposed to be the same value, and that the voltage is supposed to be different values. I performed a lab on...
  2. ISamson

    Generating Electricity Chemically and Physically.

    Hello, I have been interested in making electricity by trying to construct small generators or taking advantage of chemical reactions. I have found a bike electric generator, but I did not know how to spin it constantly. I am looking for how to make electric currents of 8-20 volts for some home...
  3. D

    Would HE light applied to mercury vapor produce electricity?

    I'm likely going to have a ton of questions in the following weeks about a wide range of particle physics etc. If (electricity X mercury vapor) = light, then multiplication being transitive, (light X mercury vapor) = electricity. Can someone inform? I've found only mercury vapor as a metallic...
  4. M

    Can you make an electrophoresis battery?

    Can you immerse an electrolyte in an external electric field such that the ions are separated to a point that you could introduce electrodes and produce current in a load solely by virtue of the established charge distribution without electrode chemical interaction or galvanic potential as shown...
  5. C

    Motion of Charged Particles in Electric Fields

    Homework Statement This is the question: An electron at rest of mass 9.11 × 10−31 kg is accelerated through a potential difference of 350 V. It then enters some deflecting plates of 50 V with dimensions as shown. Calculate the distance x (deflection of the electron) (Charge on an electron is...
  6. B

    Why do experts refer to proton current as positive electricity?

    As an electronic engineering graduate, I was taught that positive electricity was the flow of "holes" created by the absence of electrons. These holes and the vector movement are modeled as the "positive" flow of electricity. Why then do I hear experts refer to proton current as positive...
  7. P

    Component Force on a 1.0 nC Charge

    Homework Statement What is the force F on the 1.0 nC charge at the bottom in the figure? Give your answer in component form. In the figure, the +!.0 nC charge is adjacent to a +2.0 nC charge to the left at a 45° angle, a -6.0 nC charge directly above, and a -2.0 nC charge to the right at a 45°...
  8. C

    How Does Magnetism Influence Proton Movement in Electric Fields?

    Homework Statement Homework EquationsThe Attempt at a Solution Maybe the proton will move directly upwards? because that is the opposite to the direction of the conventional current.
  9. P

    Problem of electricity and electrons

    Hi, the today definition of electric current says it is done by moving electrons. But this wikipedia article https://en.wikipedia.org/wiki/Speed_of_electricity says: "the signals or energy travel as electromagnetic waves typically on the order of 50%–99% of the speed of light, while the...
  10. S

    How do planes discharge static electricity when refuelling?

    I know that planes have static dischargers (static wicks) on the trailing edges of wings to discharge static electricity when they are flying. I was wondering how a plane, let's say with electrically resistive fibreglass wings, would discharge this without having sparks ignite while it's...
  11. C

    Understanding Electricity & Charge: Rod S as Insulator or Conductor?

    Homework Statement Homework EquationsThe Attempt at a Solution I understand I, but struggle to figure out whether rod S is an insulator or conductor. Does this have anything to do with charged object attract uncharged uncharged object? Please help~[/B]
  12. C

    Electricity and Charge: Understanding Attraction and Earthed Conductors

    Homework Statement Homework EquationsThe Attempt at a Solution I chose B because I thought the positive charges in the insulator would attract the negative charges in the conductor to one side. I do realize that it is earthed for a short time. What difference does it make? Thank you
  13. C

    Help: Electricity and Magnetism Question

    Two long, parallel wires are separated by a distance of 1.0m. The current in each wire is 1.0A. What is the magnitude of the force on 1.0 m length of each wire? Help~ Thanks a lot
  14. rfranceschetti

    Engineering The relationship of a mechanical engineer with electricity

    Hi all, I have in mind that an engineering project tends to be quite "integrated", as in, it envolves different engineers. So, for instance, in order to build an aircraft, you need not only a mechanical engineer, but also an EE, Materials, managers, etc etc. So lots of teamwork. However, I'd...
  15. P

    Magnitude and Direction of the Force on a Charge

    Homework Statement What is the force F (a vector) on the -10 nC charge in the figure? Give your answer as a magnitude and an angle measured cw or ccw (specify which) from the +x-axis. The figure shown is in the shape of a rectangle. On the top left is a +15 nC charge; on the top right is a...
  16. B

    Electric Potential and Electric fields

    Homework Statement Can there be a point in space where there is an electric potential but not electric field? Can there be a point in space where there is an electric field but no electric potential? Explain you answer. What would the electric field lines look like if the electric field was...
  17. S

    Electricity (charge on capacitor in circuit)

    Homework Statement A capacitor of is connected as shown in the circuit. The internal resistance of the battery is Amount of charge on capacitor plates will be : Homework Equations no relevant euqations given. The Attempt at a Solution I don't even know how to begin with the question:(...
  18. S

    Electricity (Potential difference between points in circuit)

    Homework Statement In the circuit shown, what is the potential difference VPQ? Homework Equations No relevant equations given in question The Attempt at a Solution Tried kirchhoffs law. Tried to find equivalent battery and resistance but that doesn't seem to be possible.
  19. J

    Wireless Electricity Transmission

    Folks, I am still thinking of the possible approach to solving a problem of having to run poles and power lines to transmit electricity from one point to the other. Can there be a way it could be done in that we can convert electric current into electro-magnetic waves that can be transmitted...
  20. Sunbodi

    What is the Electric Flux through a Net in a Uniform Electric Field?

    Homework Statement [/B] A butterfly net hangs from a circular loop of diameter 400 mm . You hold the loop horizontally in a region where the electric field is 150 N/C downward, as shown in (Figure 1) . What is the electric flux through the net? Homework Equations k = 9E9 N E = kq/r2 Flux = Q...
  21. R

    Finding resistance and its change from a V-I graph

    Homework Statement The question reads: The following graph shows the relationship between voltage V and current I, through a particular electrical component. (The line in graph is straight, not showing properly in the photo) What is the electrical resistance of this component when the...
  22. unseeingdog

    Final charge on capacitor for an RC circuit

    Homework Statement Homework Equations ##q = CE(1 - e^{-t/RC})##The Attempt at a Solution I assumed that, since the problem specifies that sufficient time has passed, it meant to say that enough time passed. thus making the exponential term in the equation go down to 0, and the charge in the...
  23. K

    Static Electricity powered toy car project for school

    I have to make a project for school, so I thought that i can make a static electricity car. I wanted to make a car, and stick/put a material behind the car which creates a charge, and then take another material which creates a charge, and rub it. As it creates static electricity, the cars...
  24. B

    Losses on Power Transmission Lines

    Say a power station transmits 1008 MWh of power per year to a facility however they only receive 900 MWh say the transmission line is 15 km long how would you calculate average power loss per km, now I know that theoretically it will just be 7.2 MWh per km but what calculations would you make to...
  25. F

    How do conduction tobacco vaporizers create heat?

    My friend and I were planning on possibly developing our own tobacco vaporizer, but we lack the electrical engineering knowledge. We know they are simple devices with few parts, (a battery usually being the largest one) and we just were not sure how exactly the electrical energy was transferred...
  26. ShaddollDa9u

    Potential difference across capacitor

    Hi, the solution of my exercise says that the potential difference in the capacitor C1 is zero. Can you please explain me why it's the case ? Thank you.
  27. Narayanan KR

    Dynamo design with regenerative back mmf

    In the above presented dynamo design, three snapshots taken during three instances during the rotor running. In fig 1 the approaching magnet builds an induced voltage across the coil, however the circuit is still open, hence no current flows. In fig 2 when the rotor reaches TDC (top...
  28. M

    Reactions to produce electricity

    I am looking for reactions that can power a small car. I'm currently working on a college project where we have to make a car powered by a chemical reaction. Could anyone guide me in the right direction?
  29. A

    Why does this bulb get brighter after the switch is closed

    Homework Statement Homework Equations None The Attempt at a Solution The answer is B, bulb B will be brighter than before. My thought was that initially, the current gets split so that 2/3 I0 goes to the branch with 2 bulbs, since it has twice the resistance of the first branch, and that...
  30. S

    What is the magnitude of the electric field (rod)?

    Homework Statement Two thin glass rods are placed side by side 4.70 cm apart as shown in the diagram below. They are each 11.3 cm long and are uniformly charged to +10.4 nC . Answer the questions below regarding the electric field along a line which is drawn through the middle of the two glass...
  31. Epoch

    Electricity: voltage calculation in serial

    Homework Statement Calculate the voltage U. The voltmeter gives a value of 80V. The Attempt at a Solution [/B] 3RI + 4RI - U = -80 How can I create a System of Linear equations if I have only one equation? Do I miss something? My answer sheet says U = 150V.
  32. Additya

    B Can a wire be called a resistor?

    Can a wire be called a resistor? Also do all circuits require a resistor? If no then give an example of a circuit which doesn't have a resistor. Please thanks
  33. K

    What is the effective resistance between X and Y in this circuit?

    Homework Statement Find the effective resistance between X and Y. I have attached the circuit to this post. Homework Equations V=IR The Attempt at a Solution I did 0.25+0.5+0.5=1.25 then flipped the fraction to get 0.8ohm. I considered as if two resistors are connected in series and rest are...
  34. Epoch

    Electricity: shunt calculation for ammeter

    Homework Statement We have an ammeter with 20Ω resistance and a range of 10mA or 0.01A. The different ranges are 3000mA, 300mA, 30mA. Calculate the shunt resistors a, b and c. Homework Equations The Attempt at a Solution Ia = 0.01A ; Ra = 20Ω ; I = 0.03A Ua = Ia ⋅ Ra = 0.01A ⋅ 20Ω =...
  35. Epoch

    Electricity: ammeter range calculation

    Homework Statement [/B] An ammeter has a range of 10mA or 0.01A and a resistor of 20Ω. Three shunts are used: R1 = 4Ω ; R2 = 2Ω ; R3 = 4Ω What will the different ranges be (m3, m2, m1)? The Attempt at a Solution [/B] I started by calculating the voltage: Ua = Ia ⋅ Ra Ua = 0.01A ⋅ 20Ω =...
  36. K

    Electricity, voltage, current, resistance relationship

    Hi, The Circuit I am referring to is a simple series circuit with the resistance of the wire is negligible. I am confused about the fact that if we increase the resistance of a resistor in a circuit, the PD across the component will also increase. From my understanding I thought increasing the...
  37. D

    Is generating electricity from rain water efficient?

    From small generators attached to the gutters of your house to large ones in the storm sewers, is it efficient enough to make the effort?
  38. K

    Electricity -- Effect of heating a thermistor in this circuit

    Homework Statement The thermistor is heated so that its resistance decreases. State and explain the effect this has on the voltmeter reading in the following positions. A–C Homework Equations V=IR[/B] The Attempt at a Solution :[/B] I will say that the voltage will increase because if the...
  39. Jane Bondarenko

    Salt concentration and its electrical resistance

    What would be the theoretical relationship between/ a formula for the salt concentration in distilled water and its electrical resistance?
  40. Jamison Bond

    HHO Easy Recombination to get electricity

    I was just wondering if there is an easy way to recombine hydrogen in a fuel cell style but effectively by doing electrolysis in reverse. Splitting is really easy but is there a way to get the HHO to recombine into water and release electricity effectively by reverse electrolysis? I get that...
  41. P

    I The Electric field of a moving charge according to Purcell

    In Berkeley Physics Course (Volume II) on Electricity and Magnetism: https://www.scribd.com/doc/128728926/Electricity-and-Magnetism-Berkeley-Physics-Course-Purcell ...Purcell discusses the invariance of charge (Section 5.4), the electric field measured in different frames of reference (Section...
  42. B

    Conceptual Understanding for Voltage in a Circuit

    I'm having trouble understanding circuits, particularly voltage. So my question is more of a conceptual dilemma. Please correct my definitions and relations if it is incorrect. Voltage is the energy provided per charge, and this energy is converted to KE once the circuit is closed, or in other...
  43. G

    References on thermal power stations and supercritical technology

    Hi. This is technically an assignment question, but it's not really a problem that I have to solve. It's more of an investigation so I thought this would be a more appropriate place to discuss it. The question basically asks you to compare the thermodynamic cycle of water in a typical thermal...
  44. Arceus74

    What is Electricity? Insights please....

    I have some couple of questions about this topic to keep this as concise. 1)First of all why does electricity flow in the opposite direction to electron flow? 2)What is electricity in relation with a electron? I know it is the proportional to electric charge, but what relation does it hold? Is...
  45. E

    Finding electric potential between two concentric spheres.

    Homework Statement A spherical shell with inner radius A and outer radius 3A which has a uniform charge density, i.e charge per unit volume, p0. Find difference in electric potential between the center of the shell and a point a distance 2A from the center. Homework Equations The answer given...
  46. V

    Find electric potential of field inside and outside nucleus

    Homework Statement Derive following expression for the electrostatic potential energy of an electron in the field of a finite nucleus of charge, ##+Ze##, and radius, ##R=r_0A^{1/3}##, where ##r_0## is a constant. (Charge density is constant.) The potential we are asked to derive is: $$ V(r) =...
  47. S

    Can Ionizing Radiation Be Directly Converted to Electricity?

    Is there any way to convert ionizing radiation to electric energy without converting it to heat in the meantime? I don´t mean avoiding losses as heat - these are unavoidable - but direct conversion of some energy to electricity, by a mechanism that does not depend on buildup of heat. For...
  48. W

    Which Equations Apply When a Dielectric is Inserted into a Live Capacitor?

    Homework Statement Below are a few equations listed in my text for use in calculating capacitance in dielectrics. I'm wondering which of these are applicable in specific scenarios Homework Equations 1. k = C/C0 - with C0 indicating capacitance w/o dielectric 2. v = v0/k 3. E = E0/k 4. σi = σ(1...
  49. nipunsainni

    Engineering What Are the Best Resources for Learning Electricity and Transformers?

    Hi everyone, I want to self study about the electricity and all other basics which are required to understand the making and working of transformers. Then I want to study the making and working of transformers. Please suggest me some good book which I should refer to get the required...
  50. I

    Calculating Input Voltage of a Step Down Transformer

    Homework Statement A pair of power transmission lines each have 0.68-Ω resistance and carry 650 Amp. If the primary voltage of the 10:1 step-up transformer is 4.6 kV, calculate the input voltage of the step-down transformer at the other end. Homework Equations P=IV V=IR IpVp = IsVs The...
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