Questions tagged [electricity]
The study of the presence and flow of electric charge. Charges, currents, fields, potentials.
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Were radioactive materials used in neon indicator lamps? [closed]
Were radioactive materials used in neon indicator lamps?
Old-fashioned glow starters for fluorescent lighting
[How a glowstarter works]
often contain small traces of radioactive gas (like $^{85}$Kr or ...
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Hi, I have a doubt in a question related to capacitors, can someone please check [closed]
a parallel plate capacitor is charged and then disconnected from the source of steady EMF. The plates are then drawn apart farther. Again it is connected to same source.
Then incorrect option is (And ...
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Confusing definitions of EMF
I was studying about EMF (electromotive force) recently but had trouble connecting the two definitions of the topic. Here are the two definitions of EMF listed in my book (The book I've referred is: ...
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The temperature of a metal wire rises when an electric current passes through it because- [closed]
The options given were-
A)Collison of conduction electrons with each other releases heat energy
B)When the conduction electrons fall from higher energy to lower energy level heat energy is released.
C)...
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Can a satellite generate electricity by using a planet's magnetic field? [duplicate]
I am entering AP Physics E&M and don't have much knowledge about electricity but always had an idea based on my limited knowledge.
If a satellite had a metal coil inside of it, wouldn't it have an ...
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Understand power rating in layman terms
I have recently started the chapter of electricity of class 8. I am not understanding the concept of power rating of appliances. When we say that a bulb is rated 220V-100W, which means, according to ...
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Volume distribution of charge in a wire in a DC circuit
According to this and several other articles some amount of charge in a DC circuit distributes itself on the surface of the conductor, making the electric field inside parallel to the said surface.
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How do I compute the voltage accross a cell membrane given microstate of neuron (distribution of charged ions)?
I am not a physicist, and I'm not sure what keywords to use to search for this.
I'm trying to understand how I could in theory quantitatively know, what the voltage across a cell membrane in a Neuron ...
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Is charge an intrinsic property of matter? [duplicate]
Is charge an intrinsic property of all the particles that comprise matter or is it an intrinsic property limited to certain fundamental particles only??
Or the question can be revised as "Does ...
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Do we have to provide energy to move electrons in an electric field?
In the positive and negative terminal of a battery, there is potential difference due to the accumulation of charges in their respective terminal, so it created a potential difference, and if we ...
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Induced charge on conducting sphere sliced by a plane
We are given a conducting solid sphere, and it is cut by a plane as shown.
A charge $Q$ is given to the smaller part of the conductor, and it is required to find the induced charge on the surface of ...
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Gibbs phase rule argument about battery voltage dependency on the state of charge
I'm studying battery physics, particularly the dynamics of full discharge, and I am having trouble understanding an argument that is based on the Gibbs phase rule
$$F=C-P+2.$$
I understand the phase ...
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Does all the Energy provided by the battery dissipate into heat?
Before proceeding onwards please note that I am talking about a simple circuit consisting of an ideal battery, a switch and an external resistance.
So I was told that $$ W_\text {ideal battery} = Q_\...
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Is there simple harmonic motion when a dielectric longer than the capacitor is inserted into the capacitor? [duplicate]
I’m trying to understand the mechanics of a dielectric being inserted into a parallel-plate capacitor. Suppose I have a parallel-plate capacitor with plate separation d and a dielectric slab of length ...
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Why does the electric field only depend on the rod?
In the following exercise:
We are asked to calculate the electric field at a certain distance from an exis where a rod is located. Previously, we are asked to calculate the charge density a ...
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Is the Lorentz force proportional to $B$-field in the wire or immediately outside of it?
When considering the force on a current carrying wire in a magnetic field, is $B$ in the Lorentz force $F=IlB$ the field inside the wire where the current is flowing, or is it the field immediately ...
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Resolution of current in solenoid in order to analyze magnetic field?
So i came across this question in one of my tests, it asked something appearing very easy,It actually asked "If radius of solenoid is R and that of wire wrapped on it is r then comment about the ...
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Energy stored in capacitors [duplicate]
I have read a few answers justifying how the energy loss takes place when a capacitor is charged, that is half of the energy produced by battery is lost. The answers for RC circuit and others makes ...
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Confusion about EM waves in a conductor, AC in wires, and skin effect
I am trying to get my head around these different points:
From Maxwell's equations we find that an electromagnetic wave in a conductor decays in amplitude with a characteristic length of about 1 cm in ...
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Are electrostatics conditions still valid in Current carrying conductors?
Question 1: How is steady Electric field generated inside a conductor ?
Question 2: Why do we say that electrostatic conditions still hold in a current carrying conductor(drift speed is small ...
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Predicting electrical mean free path in nanostructures?
How does one roughly predict the
mean free path for
electrical conduction
in a nanostructure at different temperatures and under different electrical conditions such as different voltages and ...
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Maximum mean distance electrons can travel in ballistic conduction?
How far in mean distance can electrons reasonably travel via ballistic conduction according to the current model and what is the current mean or average distance or length record for ballistic ...
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Charge transferred from Sphere and Disc after being brought into contact
Recently I came upon the following question $-$
A conducting sphere of radius $R = 1 m$ is charged to a potential $V = 1000$ volts. A thin metal disc of radius $r = 1 cm$ mounted on an insulating ...
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Atomic Level Explanation of Active Cathodic Protection
I was trying to understand why active current cathodic protection doesn't work for cars and I realized I don't really understand what's going on with cathodic protection at an atomic level.
I ...
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Why do different ways of calculating the new capacitance of a capacitor after being partially filled with dialectric yield different results? [duplicate]
I have encountered this problem that stumped me and my colleagues. It is expected to be solved by Physics II students. I tried asking some faculty members but to no avail.
An air-filled parallel ...
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Derivation and theory for $I = kV^n$ [closed]
I performed an experiment in college to study the nature of a filament of a lamp, determine $k$ and $n$ in the relation mentioned, and study the variation of wattage of a lamp. I assume ohm's law is ...
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Why is the energy lost by an electron in passing though the LED = energy of the emitted photon?
I understand that the energy of the emitted photon = energy between the conduction band and valence band, but why does the work done by pushing the electron through the depletion region equal the ...
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About lightning and lightning conductor
Lightning not only strikes on a lightning conductor installed on the building... Lightning can strike anywhere on the surface roof of the building even though that building has installed a lightning ...
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What limits the size of a nuclear power generator?
Nuclear microreactors like Westinghouse's eVinci are small enough to fit on a flatbed semi-truck, and NuScale Power's small modular reactor (SMR) is small, too; but are there smaller nuclear power ...
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If metals can’t sustain an electric field inside them (as their electrons move to cancel it out), how do they still conduct electricity? [duplicate]
I tried to understand by my own couldn't do so.
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