Electric charge Definition and 272 Threads

1. Homework Statement In a certain region, the Earth's magnetic field has a magnitude of 5.30e-5 T and is directed north at an angle of 57° below the horizontal. An electrically charged bullet is fired north and 11° above the horizontal, with a speed of 681 m/s. The magnetic force on the...

Homework Statement Measurments indicate that there is a weak electric field of 150 N/C surrounding the Earth that points towards the center of the earth. Determine the absolute value of the electric charge of earth. Homework Equations F|e| = ma |E| = |Fe| / |qt| |E| = k|qs| / r^2...

Say, all objects in a closed Universe are neutral, and there is only 1 (unbalanced) positive charge. Lines of an electric field started on a positive charge can end only on the negative charge or they go into infinity. But in a closed universe there are no negative charges nor they can go...

Hi, If I have a Lagrangian of complex scalar field (just U(1) local invariance). And I know that phi^star describes field with -e electric charge and phi describes field with e electric charge. How do I apply "charge issue" when I write Lagrnangian after spontaneous symmetry breaking in...

Homework Statement A point charge q = -8 μC is surrounded by two thick, conducting spherical shells of inner and outer radii a1 = 0.3 m, a2 = 0.4 m, a3 = 0.7 m, and a4 = 0.8 m respectively. The inner shell is uncharged; the outer shell has a net charge Q = -10 μC. At this point in the...

If I have a really big charged object, is it possible to direct the charges to an object/the same place and generate current/electricity from it? It was just something I thought of, totally random, but I'd like to know the reasoning behind it C:

Homework Statement Human tissue contains about 3·10^27 electrons per kg of material. Suppose two humans each have a mass of 50 kg. We now transfer 0.0005 % of the electrons from the male human to the female. What are the net charges of the two humans afterwards? Homework Equations 1...

Homework Statement hello, the problem is that i have charge q which lies in d distance from a plane and I need to find function \sigma which describes density of this charge The Attempt at a Solution I wrote this situation in cylindrical coordinate system where q lies in point A=(0,0,h) and...

Homework Statement A charge of 6.00 mC is placed at each corner of a square 0.100 m on a side. Determine the magnitude abd direction of the force on each charge. Homework Equations The Attempt at a Solution

Hey there, So I'm a bit of a newbie on this, and I'm just kind of wondering on this subject... But could someone give a brief description of how conservation laws apply to electric charge? And more specifically, I'm thinking in terms of how it applies to synapses and such in the brain...

1.If you charge a pocket comb by rubbing it with a silk scarf, how can you determine if the comb is positively or negatively charged? 6.Contrast the net charge on a conductor to the "free charges" in the conductor. 7.A charged rod placed near an unchanged metal object can attract(or repel)...

Homework Statement The Earth can be regarded as a sphere of radius R, the volume density of charge distributed as \rho = \frac{\rho_s r}{R} where the density is 0 at thcce centre and rises linearly with radius until it reaches ps at the Earth's surface i) prove that the total charge on...

I'm not a science student. So, I humbly request you to limit yourself to the basics, please do not indulge in infighting. If you ignore the request, you would be investing your efforts at the wrong place and perhaps it would be considered a pretentious show of knowledge. If a gold leaf...

According to the third paragraph over here, http://www.particleadventure.org/quarks.html "Quarks have the unusual characteristic of having a fractional electric charge, unlike the proton and electron, which have integer charges of +1 and -1 respectively." What does the fractional...

In electronics it is customary to define the potential of ground (thinking of the Earth as a large conductor) as zero. Is this consistent with the fact that the Earth has a net electric charge that is not zero?

Two rods, one brass and the other plastic, have been charged by contact at one end by an ebonite rod rubbed with fur while being supported by an insulator. Compare the distribution of electric charge on the two rods.

Homework Statement which quantity of excess electric charge could be found on an object 1) 6.25 x 10 exponenet -19 c 2) 4.80 x 10 exponent -19 c 3) 6.25 elementary charges 4) 1.60 elementary charges Homework Equations i know that 1.60 x 10 exponenet - 19 c is one element charge...

Homework Statement A point charge Q lies along the axis of symmetry between two half-infinite grounded conducting plates which form an angle theta (less than or equal to 90 degrees). a. What are the magnitudes and locations of the image charges? b. What is the total charge on the...

There are two spherical hollow conducting shells, one inside the other. The outer shell has a radius 4 times that of the inner shell. There is a switch connecting the two shells, which is for the moment, open. Both shells have a positive charge (inner shell = +20nC and outer shell = +60nC...

Homework Statement How many rice grains are needed for an electric charge of a certain strength (I don't remember the value now but is it really relevant?) to be equally distributed amongst them? Homework Equations I hope you can answer that :) The Attempt at a Solution I can...

Hey. I am trying to solve the following problem: Given a spherical shell with radius a and charge density sigma. If a very small patch of this surface were removed, leaving a small hole, what is the electric field just above and just below this hole? For the electric field below the hole, I...

Homework Statement A small sphere with a charge of 2.36 microCulombs is attached to a relaxed horizontal spring whose force constant is 88.6 N/m. The spring extends along the x axis, and the sphere rests on a frictionless surface with its center at the origin. A point charge Q = - 8.55...

Homework Statement Referring to the figure, suppose q_2 is not known. Instead, it is given that q_1+q_2=-1.0. The figure is q1 q2 q3 all lined up in a row with q2 being negative and q1 and q3 being positive as the electric field lines from both q1 and q3 point towards the negatively charged...

Homework Statement Charge Q is on the y-axis a distance a from the origin and charge q is on the x-axis a distance d from the origin. What is the value of d for which the x component of the force on q is the greatest? Homework Equations The Attempt at a Solution

Does a moving charge create a magnetic field? At first the answer was obvious to me, since I = Q/t then if a charge is moved it is simillar to an electric current, and electric currents create magnetic fields. However in a conductor, an electric current consists of electrons moving past...

Homework Statement In a frame S, two identical particles with electric charge q move abreast along lines parallel to the x-axis, a distance r apart and with velocity v. Determine the force in S that each exerts on the other, by use of the force law for a uniformly moving charge. I would...

Homework Statement 13 equal charges, q, are situated at the corners of a regular tridecagon. What is the net force on a test charge, Q, situated at the centre. Homework Equations F=k(qQ/r^2) r^ (r^=r vector/r) The Attempt at a Solution The net force will be zero due to the...

Homework Statement Find the negative electric charge of all the electrons in a 56 liter sample of oxygen gas at STP. Assume the oxygen gas is diatomic. Homework Equations The Attempt at a Solution I have no idea. Please help

We know that the negative charge on the electron and the positive charge on the proton are equal. Suppose, however, that these magnitudes differ from each other by 0.00007%. With what force would two copper pennies, placed 1.2 m apart, repel each other? Assume that each coin contains 3...

Hey. I'm just doing a lab an electrostatics and my coursebook suggests a number of materials to use, however, I'm not really getting clear reactions with them. The purpose of the lab is to create an electrostatic series. I first have to establish a reference material; I chose cellophane or...

I was going through wikipedia and other online 'resource' sites trying to to find an answer to this question, and the answers I came across were difficult for me to interpret. Obviously in general terms the Neutron has a charge of 0 but I remember once reading a few years ago that it might have...

Dear cosmologists, how do we know the total electric charge of the Universe ? For instance the matter-antimatter asymmetry was a part in (say) 10 billions. But gravity is 40 order of magnitude less intense than electromagnetism, so I need an asymmetry 30 orders of magnitude less for electrical...

Homework Statement A charge Q1 = 0.0306 μC is located a distance d = 4.17 cm to the left of another charge Q2 = - 0.0206 μC. a. At what point along the line joining the charges is the electric field zero? Give your answer as the distance x from the charge Q2, positive if the point lies to the...

Homework Statement three point charges q1,q2&q3 are place at the vertices of triangle as shown in the diagram charge q1 has been given 4.5 X 10^13 extra electrons, charge q2 given 9.0 X10^13 extra electrons and q3 has had 9.0 X 10^13 electrons taken from it. Calculate the electric charge of...

Homework Statement The force exerted by an electric charge at the origin on a charged particle at point (x,y,z) with position vector r = <x,y,z> is F(r) = Kr / |r|^3 where K is a constant. Find the work done as the particle moves along a straight line from (2,0,0) to (2,1,5). Homework...

Peter Bergmann (a student of Einsteins) in THE RIDDLE OF GRAVITATION, PAGE 60 notes And here I had been thinking only about the speed of light as invarient. Is the above coincidence?? I can't tell... and the space time interval, is also invarient, right?? Are there other entities...

Homework Statement A nonconducting disk of radius a lies in the z = 0 plane with its center at the origin. The disk is uniformly charged and has a total charge Q. Find Ez on the z axis at the following positions. (Assume that these distances are exact.) Z = a [__________]Q / (a2εo) - This...

Homework Statement Consider three identical metal spheres, A, B, and C. Sphere A carries a charge of +5q. Sphere B carries a charge of -q. Sphere C carries no net charge. Spheres A and B are touched together and then separated. Sphere C is then touched to Sphere A and then separated from...

consider a circular clock face of radius= 50cm.a charge of 3nC is placed at the 3 o'clockpoint (a distane of 50cm from the center of the face). a charge of 6nC is placed at the 6 o'clockpoint.9nC is placed at the 9 o'clockpoint and 12nC is placed at the 12 o'clockpoint. what is the electric...

Homework Statement A charged water droplet of radius 0.02 mm remains stationary in air. If the electric field of the Earth is 100 N/C downward,what is the charge on the water droplet? By comparison with its neutral state, how many electrons must the water droplet have gained or lost? [...

Hello everyone, my answer on the following problem is wrong and I don't see why. I am translating the question from another language, I am sorry if the english is not clear. Let q1 = 27C localised at x=0, and another charge q2=3C localised at x=1 meters. a)Besides infinity, find a point...

Homework Statement The figure below shows charged particle are fixed in place on an axis. In which situation is there a point to the left of the particles where an electron will be in equilibrium? Homework Equations F=\frac{KQ_1Q_2}{r^2}? The Attempt at a Solution The solution says...

Homework Statement Electric Charge is distributed over a thin spherical shell with a density which varies in proportion to the value of a single function P_l(cos \theta) at any point on the shell. Show, by using the expansions (2.26) and (2.27) and the orthongonality relations for the...

There is a picture for this question so I will try to describe it to my best ability. Two small spheres, each with mass m=3g and charge q, are suspended from a point by threads of length L=.22m. What is the charge on each sphere if the threads make an angle of 15 degrees with the vertical...

A container holds a gas consisting of 1.75 moles of oxygen molecules. One in a million of these molecules has lost a single electron. What is the net charge of the gas. 1.6 x 10^-19(C/e^-) x n(e^-) So I'm looking for the number of electrons (n) which I think is 1.05625 x 10^19 and...

Homework Statement Two small spheres, each of mass 8.00 g , are suspended by light strings 15.0 cm in length (see figure). A uniform electric field is applied in the x direction. The spheres have charges equal to -6*10^-8 and 6*10^-8 Determine the electric field that enables the spheres to...

Hi all. I need some help. Without using Gauss's Law, I have to derive the formula for the electric charge for different cases. -I already did few cases such as: 1. Infinite line of charge 2. Semi - infinite line of charge 3. Ring of charge 4. Semi - Ring of charge or any arc of charge 5...

Homework Statement A charged sphere is suspended by a nonconductive string in a uniform horizontal electric field. The electric field exerts a force on the sphere such that its equilibrium position is diplaced at an angle  = 30° relative to the vertical, as shown in the diagram below. The...

Homework Statement (Note: Don't worry about significant digits. I just want to be able to do the question and will worry about significant digits on the exam.) In the figure below, a non-conducting spherical shell of inner radius a=2.00cm and outer radius b=2.40cm has (within its...

The basic law of electric charge fields is that like charges repel and unlike charges attract. This does not come out of the equations but is inserted as just an empirical observation that must be allowed for, is it not ? Am I missing something here? Compare gravity that is always an...