Questions tagged [electricity]
The study of the presence and flow of electric charge. Charges, currents, fields, potentials.
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energy consumption calculation in a DC circuit
I'm working on the simulation of a current and voltage limiter circuit in a simulation and I'm not sure in the following pretty basic calculation:
I have an ideal voltage source with the voltage of ...
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2answers
45 views
Why does current remain same in a series circuit?
Current is the rate of flow of charges with time. When passing through each resistance in a series circuit, charges lose energy and "slow" down due to collisions with atoms (metal cations). When time ...
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2answers
60 views
Resistance of an object with arbitrary shape
Suppose to have a conductor with a non-trivial geometry, like the one in the picture:
The shape does not really matter for this question, as long as you suppose to have at least one "hole" in the $z-...
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1answer
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What is the change in the form of energy that is shown by the change in direction of the compass needle when an electric current is passed beneath it?
If the magnetic field generated by the electric current does not move the compass needle, no work is done, thus no energy is exchanged. If the magnetic field generated by the electric current does ...
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0answers
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Electric Field between two charged particles [on hold]
Using the coulomb force formula, find the electric field between any two charged particles of our choice.
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0answers
14 views
Current through the secondary of a transformer
If I know the wattage of the primary of a transformer, and the input voltage, how do I calculate the current flowing through the secondary, if a load of some resistance is placed across the secondary?
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0answers
13 views
Electric Potential and conservation of energy [on hold]
An infinitely long line of charge has linear charge density 5.00×10−12 C/m . A proton (mass 1.67×10−27 kg, charge +1.60×10−19 C) is 18.0 cm from the line and moving directly toward the line at 4.10×...
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0answers
17 views
24a battery on a an engine that needs 14a only? [on hold]
Can you actually use an 24a battery on an engine that was made for a 14a battery using resistors ?
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2answers
32 views
What is the reading of a voltmeter if the EMF is 12 V and internal resistance is 3 ohms [on hold]
A battery has emf 12.0 volts and internal resistance 3.00 ohms. A voltmeter is connected to the terminals of the battery; the battery is not connected to any other external circuit elements. What is ...
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1answer
35 views
How to calculate total power generated?
I have a circuit with a piezoelectric transducer which converts mechanical energy to electrical. The ceramic is connected to a 1 Megaohm resistor and a voltmeter which reads voltage.
If I want to ...
3
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1answer
47 views
Are Electrons in a Circuit Subject to Newton's Third Law?
Consider a simple electrical circuit made up of a battery, an incandescent bulb, and wire. The battery and bulb are equal in mass and are on opposite sides of a circle made up by the wire. Lastly, the ...
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3answers
86 views
Why is resistivity of conductor inversely proportional to the area of the conductor?
A simple Physics question regarding Ohm's law. The resistivity of the conductor is inversely proportional to the area of the conductor. I would like to have a simple explanation for this.
How does ...
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2answers
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What the voltage, electric field, and potential energy in the center of grounded concentric conductor spheres? [on hold]
the a shell is charged with 120v
while the surfaces of b is grounded
What is the voltage in the center of shells (vo)?
The electric field in the center of shells?
The potential energy in the center ...
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3answers
75 views
Summing up very basic terms in basic electricity [closed]
My attempt to define following terms as per my understanding. I am currently at high school.
Electromotive force (EMF): Potential between two terminals when open circuited.
Wikipedia's ...
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4answers
81 views
How does an antenna capture the energy of EM radiation?
I am having trouble reconciling the descriptions I have read of how antennas work to recieve and transmit radiation.
My simple understanding is that in recieveing the oscilating electric field of an ...
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0answers
42 views
Why can’t we use the other formula for heat in this?
Two conducting wires of the same material and of equal lengths and equal diameter
are first connected in series and then parallel in a circuit across the same potential
difference. The ratio of heat ...
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2answers
39 views
What happens when a battery is dead?
While studying circuits I am having a question that when we say a battery is dead.Do we mean that the voltage difference between the ends has become zero?If no,then what actually happens?
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3answers
36 views
Flow of charges inside a battery
I am having confusion about the flow of charges inside a battery which is connected to Circuit.
Question is, do charges move from one end to another through the battery? If yes, how? Do they move ...
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5answers
103 views
Does V=IR define resistance for any conductor? [closed]
Just wanted to confirm if the statement is always true or not
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1answer
20 views
Electric fields and electric potentials in semiconductors
The zener diode is heavilier doped than a normal diode , that is why its depletion region is smaller than the delpetion region of a normal diode and that is why the electric field is very strong.Zener ...
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0answers
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Zener diode electric field working principle
Well I recently saw a video from khan academy about zener diodes.This video was suggested by another member of Stack Exchange Physics who I thank him very much . But I didnt understand some things:...
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1answer
42 views
Confusion with electric field in a capacitor circuit
I'm having a confusion involving a couple of laws for a capacitor:
$C = \frac{Q}{V} \propto \frac{1}{d}$. The capacitance, the amount of charge the capacitor can hold for a certain voltage between ...
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2answers
78 views
Why do I get static shock due to wool, but not due to cotton?
I have experienced electrostatic shock quite a lot of times due to woollen fiber, and as far as I can remember, never due to a cotton fiber.
Any explanation as to why this happens?
Edit
I ...
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4answers
94 views
Electrons flow in Circuits
The electric field created by a battery through a section of wire in a series circuit is constant. This means that the force on each electron as it travels through the wire is constant.
According to ...
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3answers
54 views
What actually current is? [closed]
Somebody help me visualizing current. What is it actually? Not just with mathematical relations but with something that we can visualize too.
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2answers
328 views
When the voltage is increased does the speed of electrons increase or does the electron density increase?
I am just a high school student trying to self study, please excuse me if this question sounds silly to you.
I know that current is a product of the speed of electrons and the electron density.When ...
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0answers
19 views
How does electricity flow through batteries connected in a series circuit?
From what I’ve learned, a single battery hooked up to a closed circuit will allow the free electrons built up at the anode of the battery to travel from the wire to the cathode of the same battery, ...
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2answers
48 views
Why doesn't a capacitor oscillate like a pendulum around equilibrium when discharging
Why doesn't a capacitor behave like a swinging pendulum when discharging? Please note that I'm not asking about solving the differential equation, but rather about how we are constructing it. I have ...
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1answer
30 views
Which types of collisions contribute to electrical resistivity?
Do electrons only bump with other electrons in a circuit and that only causes resistance? Or do they bump with the nucleus as well?
Here's a post I have been studying recently:
The path of a ...
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2answers
52 views
Why did a 12V battery affect my motor more than two 9v batteries in series?
In class, we made a coil of wire and used it to make a simple electric motor with a magnet. I put two square 9v batteries in series for a total of 18v to power the motor.
I then used a larger 12v ...
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6answers
369 views
In aluminum, how does electricity travel through the surface oxide layer?
Suppose I connect a conductive wire (cross section 1 mm$^2$) to an aluminum object. Since aluminum is highly conductive, electricity will flow smoothly inside the object with little resistance. ...
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2answers
85 views
Why does the flow of charge even create electricity? [closed]
Okay this is a question I’ve asked a lot of places but I always get its the flow of charges and it’s like a property. What I don’t really understand is how is this flow of charges creating electric ...
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1answer
42 views
Do electrons exist in shells or can they be found existing as an individual?
I am just a high-school student trying to self study,please excuse me if the question sounds silly to you.
A simple question: Are electrons always found in orbits/shells of can they even exist by ...
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4answers
59 views
Why do we use dielectric materials in a capacitor?
Okey first of I know dielectric materials used in capacitors to insulate and polarize due to electrical field created by two metal plates and then when you connect this stored energy to a system you ...
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0answers
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Electric Potential Giancoli #10
The work done by an external force to move a -6.50muC charge from point A to point B is $15.0*10^{-4}J$, if the charge had started from rest had $4.82*10^{-4}J$ of kinetic energy when it reached ...
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2answers
31 views
Is resultant power in a series circuit equal to sum of the individual powers?
This is what I did. Is this correct?
V=V1+V2
As current in series circuit is constant,
VI=V1I+V2 I
Therefore, P=P1+P2
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2answers
48 views
How does current flow in a short circuit? [duplicate]
In a short circuit, the potential difference across the terminals of a battery (consider a single cell with internal resistance)is 0 according to the equation
$$V=E-Ir,$$
where $r$ is internal ...
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3answers
63 views
Why is the current same after and before passing through a resistor? [closed]
•Why is the current same after and before passing through the resistor ?
•Why is a voltage drop across the resistor ?
Explanation in terms of electron flow and electric field will be really helpful.
...
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0answers
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Question about action-reaction pair of two wires carrying current in the same direction
Imagine two wires lined up so that they are parallel, and that they both have a current running through them in the same direction. The magnetic field produced by the current of one of the wires (say,...
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0answers
29 views
How does AC move past equilibrium? [duplicate]
From what I understand, the net movement should be zero since AC is periodic and the charges should not move anywhere.
Are they picked up by a receiver or something when they are pushed just far ...
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2answers
30 views
Trapped inside car due to live wire
My physics teacher said that if a person is trapped in a car due to live wire that is touching the outside metal of the car, then it is safe for the person to touch the outside metal of the car as ...
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4answers
658 views
How does resistance convert voltage to current? [closed]
This is a statement that I read mainly on books about electronics.
Could someone explain why after the resistance current is what makes things work and not voltage?
Example from the Art of ...
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1answer
27 views
Direct current electric circuit
Why when I reverse one of the three batteries in a torch light, the bulb does not light up?
The three batteries (one of them is reversed) and the bulb suppose to form a closed loop.
According to ...
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1answer
57 views
Two types of electric field
My textbook mentions that electric field produced by electric charge and that produced by changing magnetic field are different in nature.
After searching from various sources I found that electric ...
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2answers
54 views
What is the direction of the electricity flow in a DC circuit?
I know that in AC, the direction of the flow of electrons is constantly changing, but this question is for a DC circuit like an LED with a battery.
Does current in such a circuit flow from the - side ...
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1answer
59 views
Doubt while simulating electric circuits
Today, I was simulating DC electric circuits just for knowledge and fun using PhET interactive simulations. But I'm having trouble understanding these circuits which I made.
I think that both these ...
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1answer
39 views
How can I avoid electrostatic discharge?
I recently started an internship in an office with a rugged floor everywhere.
After a few days, I started receiving electrostatic discharge all the time after I walked a little bit around the floor (...
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1answer
16 views
Net flux through insulating cylinder
In a non-uniform electric field, say with field lines curving away from each other along x, will the net flux on a cylinder be negative or zero?
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0answers
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Difference in Electric conductivity based on connection type?
Is there a difference in electrical conductivity dipending on the way the Material is connected?
For example, is there a difference between a copper wire connected to another one „via soldering“, ...
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2answers
41 views
Accuracy of Continuous Charge Distributions [duplicate]
In E&M, it is common to represent the charge on a body with a continuous, scalar charge density function. In reality though, the body contains discrete charges. I understand why this approximation ...
