If the electric field due to an inifinitely long line of charge is given by E(r)=constant/r, then what is the change in potential from infinitely far away to r=R?
203867
At r = infinity, E(infinity) = 0.\n\nAt r = R, E(R) = constant/R.\n\nThe change is\n\nE(infinity) - E(R) = 0 - constant/R =  - constant/R.\n\nDon't drop the negative sign.
426621
v = wave length * f.\n\nSo, length = v / f =   1,7m
86506
After you obtained the flux by gauss formula, if you use it to find E then this E is not total net E and is the one produced by the charge inside.\n\nIn order to finding total E for a fixed point, you can suppose more gauss surfaces for other charge, or you can change the surface to contain other points, or you use other solutions than gauss.
24395
Strain is defined as the fractional change in length under an applied force.  Since at the instant the other wire is cut (i.e., at t=0), the remaining wire remains stationary (until it starts to stretch at a later time), the strain on that wire is 0 becuase it hasn't changed length yet at t=0..\n\nThe answer is 0.
517196
1 sum the forces and set equal to zero. 2 forces, gravity and electric.\n\n2. conservation of energy. initially all kinetic, finally all potential. KE1=U2. U2 is electric potential. solve.\n\ngood luck
153797
The electric field at a point in space is equal to force per unit charge exerted on a positive test charge placed at that point.\n\nConsider a point charge +q located at point. The charge +q sets up electric field in the space surrounding\nit. If a small positive test charge +Q placed at point P experiences a force F.Then electric field ,E=F/Q\nMind the following:\n(i) Electric field (force/charge) is a vector quantity, i.e., it has magnitude as well as direction.\n(ii) The SI unit of electric field is newtons per coulomb (N/C). As shown later, it can also be expressed\nas volts per metre (V/m).\n(iii)The other terminology used for electric field is electric field intensity or electric field strength.
284601
Since Magnetic field (B) = [K I(dl x r)]/r^3\n\nwhere I = current in the conductor\n      r = distance of the pt. from the conductor where u  want to find the magnetic field\n\nHere dl x r = vector product of small part of L i.e dl and r\n\nSee here that Magnetic field is directly proportional to Current....therefore when we increase the current by a factor of 4, magnetic field will also increase by a factor of 4.
101643
There's this equation called Coulomb's Law that relates charge and force: F=k*Q*Q/(r^2), where k is Coulomb's constant (8.988e9) and r is the distance between the two charges. That doesn't give us the units for an electric field, which is a force per charge. But we can divide both sides of Coulomb's Law by a Q, giving us F/q=k*Q/(r^2).\n\nTo find the magnitude and direction of the net electric field, you need to add together the electric field vectors created by each of the two charges. For the first charge, the electric field is k*15e-6/(.12^2)=9.36e6 N/C. The electric field of the second charge is k*10e-6/(.05^2)=3.60e7 N/C. Make sure to change cm to meters, and note that the charge q at which you are finding the electric field does not factor into our equation. Hopefully the problem describes in more detail the location of the two charges so you can determine the appropriate vector sum's magnitude and direction.
34215
The splitting and shift of a spectral line into several components in the presence of an electric field.
71401
When a plate A with no charge is brought near a charged plate B, the plate A which was originally neutral gets charged on either side.\n \nIf  B was +vely charged, the near side  of A gets negative charges because of the electro staitic attraction and the farther side of it  gets positive charges because of electro static repulsion. \n\nThe charges  induced in plate A are called induced charges.\n \nNow there exists a potential difference between A and B. If the plate A is  earthed, all positive charges in it go to the earth  because of electro static repulsion, \n\nThe potential difference increases further.\n\nThere is air in between A and B which is insulating the -ve charge of B to go to the +ve charge of A.\n\nIf the potential difference is high, the air gets ionised and becomes a conductor of electricity and charges from A go to the plate B via the ionised air medium which we call a dicharge.
186136
Possibly "statistical fluctuations in charge generation" as mentioned in ref. 1. From ref. 2, which refers to "fundamental limits imposed by charge generation statistics", I get the impression that these variations may be an irreducible error source.
514063
I am assuming the electrodes are two large parallel plates, facing each other, separated by a distance (d).  When you apply a voltage (V) across, there will be an electric field created between the plates, which will be :\n\nE = V / d\n\nThe smaller d, the higher the electric field.\n\nThe higher electric field will produce a higher acceleration in the ions, which will result in higher average ion velocities\n\nSince current is the rate of flow of charge, higher velocity will be seen as higher current.
457780
The circuit has a time constant which is calculated as\nT=L/R\n\nThe circuit will have the equation\nfor current of:\n\ni(t)=(Vs/R)*e^(-t/T)\nWhere\nVs is the supply voltage\ne is Euler's constant\n\nj
142376
It depends on the Voltage.   Imagine an electron (which has known charge q = 1.6x10^-19 and mass m = 9.11x10^-31) that is inside a wire which is a perfect conductor.   Since the electron will move in a perfect conductor, all the potential energy given by the power source (Voltage * electron charge) will transform into kinetic energy (K = (m*v^2)/2), so:\n\n(m*v^2)/2 = V*q     ;     where v is the speed of the electron and V is the voltage\n\nWith this we get:   v = (2*V*q/m)^(1/2)\n\nAll the electrons would move at this same speed, and so the "speed of electricity" is given by the above formula.   For a voltage of 110V, the kind we have at home, the speed would be:\n\nv = 6'216,016.3 m/s\n\nCompared to the speed of light:\n\nc = 300'000,000 m/s\n\nThis analysis is for didactic purpouses, since for such high speeds we would need to consider relativistic effects.   Also, remember that we don't have perfect conductors, so the actual "speed of electricity" at 110V would be a lot less than the value shown above.\n\nI hope this answer was good enough.   :)
458734
(a) The particle is held stationary between the plates by balancing the weight of the particle with the force due to the electric field, which is expressed as the charge times the electric field (F = q*E). Since the top plate is negative and the bottom plate is positive, the sphere must be positively charged (deficient of electrons) in order for the electric field to balance the particle's weight.\n\n(b) The balanced position means that the net force on the sphere is zero so that the force due to the applied field balances the weight of the sphere\n\nq*E = m*g\n\nFor the parallel plate geomtery, the electric field is expressed as\n\nE = V/d\n\nwhere V is the applied potential and d is the separation. Solving for q in terms of V and d yields\n\nq = m*g*d/V\n\n(c) The charge deficit, in this case, is then\n\nq/e\n\nwhere e = 1.602 x 10^-19 C is the value of the elementary charge.
442788
You need to get your units in a consistent form.  I suggest changing the velocity of the electron to 2.5E6 m/s so when you divide it into c-----------WAIT A MINUTE!-----Yor formula is NOT right, because you're dividing a speed by a speed, which will give a dimensionless answer.  Wavelength is a LENGTH, so the answer must come out that way.  I forget the formula you're refering to, but what you've typed isn't it................
88147
According LORENTZ LAW a force F = qv x B is exerted over a charge q that moves with a velocity v inside a magnetic field B. That force will carry electrons to one end of the conductor giving it a negative charge, leaving the other side with positive charge. Separated charges produce a electrical potential\n\n20. The magnitude of the voltage induced in a conductor moving through a stationary magnetic field depends on the LENGTH and the SPEED of the conductor.\n-----------------------------------------\n\nCopper is a non-magnetic material.\n\n21. If a bar of copper is brought near a magnet, the copper bar will be UNAFFECTED BY THE MAGNET.\n------------------------------------------\n\nthere is no resitence to the flow of current\n\n22. When all parts of a circuit are composed of conducting materials, the circuit is said to be SHORTED