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| ElecMag | This is from the AP Exam 1991 Question 2 part (a) from the free response. How do I do it?
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| ElecMag | In my exam paper, the question asked "Why is less energy loss in overhead cable when a hiher voltage is used?" I didn't answer it, the answer was because a higher voltage means lower current, and so less heat is dissipated. But I thought Ohm's law stated that voltage is proportional to current!!!!! And also, I=v/R. If R is constant how can I be lower when V is higher??????
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| ElecMag | We are two desperate high shcool Juniors from Prairie View High School in Kansas and we need as much information as possible on St. Elmo's Fire. If you could give us any information possible, it would be very helpful. Please send Thanks
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| ElecMag | Are two wires with currents in the same directions attracted or repelled?
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| ElecMag | q.1 why does the charge on an insulated conductor reduce when it is briefly put in a flame and removed?
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| ElecMag | The announcement od successful "cold fusion" research in 1989 excited energy consumers for a time. Describe what cold fusion is and the prospects for this technology. Why was this such a controversial topic at the time?
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| ElecMag | A battery of four 1.5-V dry cells in a series is connected in series with a 5.0-ohms resistor and a pair of 10.0-ohms resistors in parallel. (a)Draw the circuit diagram. (b)If the internal resistance of the battery is negligible, what is the current through one of the 10.0-ohms resistors?
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| ElecMag | Explain how an alternating emf is generated in a conducting loop that is rotated in a magnetic field. Use a diagram in your explanation.
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| ElecMag | A resistor, a capacitor, and a inductor are connected in series across a 60.0-Hz, 120-V a-c source. The resistance is 18.0-ohms, the capacitive reactance is 8.0-ohms, and the inductive reactance is 12.0-ohms. Calculate the impedance.
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| ElecMag | Two charged particle are at rest near one another, a small positve charge on the left and a much larger negative charge on the right. There is a point near the charges where the electric field due to the two of them is zero. Is it between the charges, to the left of the positive charge or to the right of the negative charge? Explain answer and give reasoning.
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| ElecMag | An electron is placed ar rest in a uniform electric field, and when it is released it begins to move to the right. Which direction does the field point in? How does the electron's electric potential energy change as it moves? How does the potential that it feels change as it moves?
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| ElecMag | When a piece of dielectric material is placed in an electric field, the dielectric produces an "induced" electric field which modifies the total electric field within the material. How does its magnitude and direction compare to the original field? Explain the origin of this induced field.
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| ElecMag | -Explain how Lenz's Law inhibits the operation of an electric motor -Explain why AC current must be used in a transformer -Compare FM and AM radio waves (how the radio waves travel from the transmission tower to your radio)
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| ElecMag | A proton is approaching an iron nucleus with an initial
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| ElecMag | A proton is approaching an iron nucleus with an initial speed of 5.05 x 106 m/s, when the proton is 20.0 nuclear radii from the iron (center to center distance). a) how far from the nucleus will the proton be when its speed is 2.03 x 10 m/s? Answer in units of the iron's radius (which is approximately 5.8 x 10-15 m). b) How close to the nucleus will the proton get? Answer in units of the nucleus' radius.
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| ElecMag | An electric dipole consists of two point charges, +-q, separated by a distance d. How much work (in terms of k,q and d) did it take to bring these charges together from a large didtance?
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| ElecMag | a proton enters a uniform magnetic filed of 0.80 T in such a way that the proton follows a circular path with a raduis of 4.6cm. what is the kinetic energy of the proton in circular motion?
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| ElecMag | a simple ac generator consists of a coil having 10 turns of wire, with each loop having an area of 50 cm2. the coil rotates in a uniform magnetic field of 350 mT with a frequency of 60 Hz. (a) write an equation showing how the emf of the generator varies as a function of time. (b) compute the maximum emf.
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| ElecMag | A cork ball covered with conducting paint is charged to -1.6E-2C. You have 3 similar but uncharged cork balls. Describe a method by which to produce a cork ball with a charge of -.2E-12C. Do you need all 3 extra balls????? Explain.
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| ElecMag | Why does lightning affect AM radio and no FM radio? I mean, they are both radio waves and lightning is a form of electromagnetism so a flash of lightning should affect both AM and FM, right? But it does not! Why???
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| ElecMag | 7. Three point charges are located at the corners of an
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| ElecMag | What is Maxwell stress?
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| ElecMag | In figure P28.21, find (a) the current in the 20 ohm re
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| ElecMag | A charge +q is at the origin. A charge -2q is at x = 2.0m on the x-axis. For what finite value(s) of x is (a) the electric field zero? (b) the electric potential zero?
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| ElecMag | Using the Dirac delta functions in the appropriate coor
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| ElecMag | The time average potential of a neutral hydrogen atom i
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| ElecMag | I am looking for the solutions manual for this book ASA
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| ElecMag | need help with calculating error on lamda max. for fin
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| ElecMag | Please help me!!! I don't understand anything to do wit
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| ElecMag | Consider the mass spectrometer shown schematically in F
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| ElecMag | Whatis an electric wind? And how is it form?
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| ElecMag | An Electron is placed between two vertical parallel plates 40 cm apart connected to a 12.0 V battery. The left plate is positive while the right plate is negative. Calculate the horizontal acceleration of the electron, then find out the velocity of the electron using kinematics if it travels all the way from the negative plate to the positive plate.
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| ElecMag | i cant understand conventional current! ahhh!
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| ElecMag | a 60 hz 150 volt ac power supply connected to a 10 ohm
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| ElecMag | for the circuit below determine Ia and Ib ie: the current for the following values for Va = -1, -0.1,1 and 2V (use the ideal diode and voltage source model
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| ElecMag | A coil whose resistance is not negligible is connected in series with a capacitor across a 20V, variable-frequency supply, the frequency being adjusted until the current has a maximum value of 0.5A. the frequency at which this accurs is 318Hz. 1) Given that the voltage across the capacitor is measured at 50V, calculate the resistance and the inductance of the coil. 2) if the frequency is doubled, calculate the change in capacitance required to keep the maximum current to 0.5A, the supply voltage remaining at 20V.
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| ElecMag | what makes up transistors and how do they work? how does an antenna work? How does a speaker work and what is it made of? How does a I.C. work?
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