All Questions
21
questions
0
votes
4
answers
71
views
Do you "lose" electricity when you course it through subpar conductors?
Imagine I had a basic circuit - say the classic 9V battery on one end, a couple of wires, and a little light bulb on the other.
Of course, in a real world example those wires would probably be ...
0
votes
2
answers
851
views
What is the meaning of unit of electrical resistivity, ohm-meter?
In the unit of work done, $Nm$, $N $ stands for the force applied and $m$ stands for the length of displacement, by taking their product we get work done or $Nm$.
But in the case of electrical ...
2
votes
1
answer
921
views
How does higher concentration leads to higher internal resistance in the cell?
Concise Physics mentions that:
Higher the concentration of the electrolyte greater is the internal
resistance(in a cell).
I think that higher the concentration of the electrolyte higher would be the ...
1
vote
2
answers
757
views
Why exactly is the resistance of a conductor inversely proportional to the area of its cross-section? [duplicate]
Before I explain my query, I would like to clarify that I am a ninth-grader who got this question while studying the formula $R \propto \frac{1}{A}$ where $A$ is the area of cross-section.
I have ...
3
votes
3
answers
235
views
What do $\ell$ and $A$ precisely mean in the formula for electrical resistance?
The formula for resistance is
$$R=\rho\frac{\ell}{A}$$
Generally in most of the textbooks it simply written that $\ell$ is the length of the conductor and $A$ is it’s cross-sectional area. But my ...
- 155
0
votes
0
answers
614
views
Current equation $I=nqA\vec{v}_d$
I was reading from several introductory E&M materials, and they all state that $$I=neA\vec{v}_d$$where $n$ is number of free charge carriers, $e$ is the elementary charge of electron, $A$ is cross-...
0
votes
2
answers
148
views
Resistance in special cases
I am curious-
I know that resistance doubles when length does, and that resistance would be halved if cross sectional area was doubled -
But is there such a case of special conditions where It ...
- 3
1
vote
2
answers
491
views
Effect of electroplating on resistance
How will resistance of a wire be affected if I electroplate it with copper will it decrease ? And if yes then will the decrease be significant?
I need to find a topic for my project I thought it might ...
- 11
0
votes
2
answers
465
views
How does the current become homogeneous within a circuit?
I have two questions:
In a given circuit with resistances of different values connected in parallel, there is a different build up of electrons when the power source is turned on. Then, how is the ...
- 1,235
-1
votes
2
answers
77
views
Some questions regarding electric properties of materials [closed]
I was reading Chapter 29 on Halliday-Resnick-Krane regarding this but couldn't understand these things.
Suppose you have a conductor in an electric field. In normal conditions the field inside the ...
- 1,195
1
vote
2
answers
376
views
What's happening at a molecular level to the resistance when the temperature of salt water is increased?
What's happening to the electrical resistance at a molecular level when the temperature of a water with a bit of salt is increased? I noticed that the resistance decreases but in metals it is totally ...
- 83
0
votes
1
answer
75
views
Point resistance
The resistance of a given object is expressed through:
$$R=\rho\frac{l}{A}$$
I'm wondering if there is any quantity like resistance at a specific point. For example, $R$ for a copper wire with l=...
- 3
1
vote
2
answers
206
views
Resistance Being Proportional to Length And Its Relation to Magnitude of Current
"Resistance of an electrical conductor is proportional to it length"
The intuitive explanation I found in many articles was that the greater the length of the conductor, such as a wire, the greater ...
- 1,387
0
votes
3
answers
1k
views
Heating of an non-ohmic conductor
So I know that if you increase the voltage across a wire then the current will increase. But an increase in current leads to a increase in heat production though $P=I^2R$, but as the temperature ...
- 273
0
votes
0
answers
37
views
How am I obtaining silicon with resistivity proportional to the number of conduction electrons?
The resistivity of silicon is given by
$$\large\rho=\rho_0e^{\Large{{\frac{E_g}{2k_BT}}}}$$
and the number of conduction electrons in a semiconductor conduction band is
$$\large n_{\text{...
- 4,607