# Tag Info

23

Quarks do not violate quantization of charge, it's simply that $\frac{1}{3}e$ instead of the electron charge $e$ is the smallest unit of electric charge.

8

That is a good question but I think you might be a bit confused. The quark charges are quantised as they are fractional values of the electron charges, so when you refer to 2/3 and -1/3 these mean 2/3 of the electron charge and -1/3 of the electron charge respectively. As such, a Hydrogen atom with a proton in the nucleus and an electron in the shell, is ...

6

This might not be quite the answer you are looking for, but one useful way to think about it is: the accelerating electron emits photons because nothing forbids it from doing so. By definition, because an electron has electric charge it is coupled to the electromagnetic field, and is able to produce excitations in this field which we can call photons. This ...

4

We can easily do this calculation. The capacitance of a sphere is: $$C = 4\pi\varepsilon_0r$$ and the charge is given by: $$Q = CV = 4\pi\varepsilon_0r V$$ The number of extra electrons is: $$n_e = \frac{Q}{e} = \frac {4\pi\varepsilon_0r V}{e}$$ And finally the mass of the extra electrons is: $$M = m_e n_e = \frac{Q}{e} = \frac ... 4 Depending on your view, there is electronics with other charge carriers. It is commonplace to have semiconductor devices where the relevant carriers are holes! Furthermore, batteries and electrolysis relies heavily on ions as charge carriers (but hardly count as electronics). I guess genuine electronics with ions will be difficult as charge carrier mobility ... 3 A capacitor stores electric energy in a static electric field between two conductors. The conductors are separated by an insulator called a dielectric, which allows the conductors to be very close to each other without contact. The closer together the conductors, the greater the storage capacity of the capacitor. This storage capacity also is proportional ... 3 Have a look at the Wikipedia article on the left hand rule. It says: The direction of the electric current is that of conventional current: from positive to negative. 3 From a classical point of view, if you look at the field lines created by charge at rest or at constant velocity you'll see straignt lines. Now if the charge changes its speed (i.e accelerating), a "ripple" will appear and propagate along those field lines. Check the animation on this page :http://www.tapir.caltech.edu/~teviet/Waves/empulse.html. You'll ... 3 It is the way one reads/writes Feynman diagrams, a particle going backwards in time is the antiparticle. The electron radiates a gamma, and continues to meet the positron , annihilating charge with another photon. Two real particles are needed for momentum conservation in the center of mass, and two photon vertices are the simplest case within the standard ... 2 Can we have electronics with charge carriers OTHER than electrons? Yes, see what Sebastian said above. And see the physicsworld article Taming light at the nanoscale: "Look around, and you will probably see numerous electronic and optical gadgets, such as mobile phones, personal digital assistants, laptops, TVs and digital cameras. These may all do ... 2 No. Step number two already mentions electrons from the battery flowing into the negative terminal of the capacitor, giving the negative terminal a negative charge. Step number three is talking about electrons flowing out of the positive terminal of the capacitor, giving the positive terminal a net positive charge. 2 Electrons flow through the wire from the battery's negative terminal to the battery's positive terminal. If said wire is actually a capacitor, the electrons still flow the same way - from the battery's negative terminal. But since it's a capacitor, the electrons are pushed into the capacitor's negative plate instead of making it all the way to the battery's ... 1 I'm assuming you mean a solid metallic sphere, not a shell. The analysis is slightly different for a shell but rests on the same principles. It is actually not correct that the total charge induced on the sphere in the case of grounding is -q. The basic concepts you need to know about electrostatics with conductors is that the entirety of the conductor ... 1 To do this you must use the electrostatic image method : The problem with two spheres is that you will have image charges of the image charges Here is a diagram of what it will look like after two iterations : Using the method of images we have the image charges inside the spheres: Q_1 has an image q'_1 located at O_2 - ( \frac{R_2^2}{D} ) with ... 1 Can you tell from the image below if Q1 and Q2 are attracted or repelled? No, you do not have enough information. Will Q2 only be attracted to the sphere if Q2 is enough bigger than Q1? For any nonzero values of Q1 and Q2 you can compute the distance at which there is no net force. Will the positive charge inside the shell attract electrons interior to ... 1 Let us imagine that the charge carriers in the rod are electrons (negatively charged). An electron moving to the right is equivalent to a (conventional) current to the left. Alternatively, you can use a "left hand rule" for electrons (since the current is to the left when the motion is to the right, you can represent electron motion with the thumb of your ... 1 To use rules without knowing what is the reason is boring. See my paper about vector product for Lorentz force, for generators and for electric drives, in a reduced form for perpendicular vectors only. If one isn't sure that this equations could be derived see this answer from mathematicans. See my answer Why does one call B the magnetic induction? too. ... 1 Begin by analyzing the forces on the two axons, x and y. You can prove that on the y axon the sum of the forces is 0. Now on x we have, for the force from the charge on +y :$$F_{1x}=F_1 cos u $$where u the angle between the x axon and the distance d between q and Q It is:$$ F_{1x}=F_1 cos u ={ k Qq \over d^2}cosu = {k Qq \over \sqrt{x^2 + y_0 ...

1

The existence of quarks is not seriously in dispute at this point AFAICT. If you want to make something meaningful out of quarks and only quarks having fraction-of-$e$ charges, I think you pretty much have to postulate that electrons are composite. For instance, the rishon model proposes that all the "fundamental particles" of the Standard Model are ...

1

If you have an isolated capacitor, so that there is no conducting path for charge to flow from one plate to the other, then the charge on the plates will be conserved as you change the geometry. Since $$Q = CV,$$ a drop in the capacitance $C$ is matched by an increase in the potential $V$. Note that the stored energy $U$ in the capacitor,  U = \frac12 ...

1

The "work" is the useful rotational pull you get from the motor, and excludes any wasted heat. If only 75% of the energy going in comes out as work, then you need to put in 90/0.75J of energy to get 90J of work out.

1

Electric charge is not special. Every charge is replaced by its opposite under the C conjugation. For instance, electric charge goes from positive to negative and vice versa. Color charge goes from blue to antiblue and vice versa. Mutatis mutandis with green/red color charge. Every charge is sent to its anti-charge.

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