All Questions
Tagged with conductors electricity
160
questions
27
votes
6
answers
14k
views
Why do metals have free electrons?
Throughout my highschool classes, I have been made to learn that metals have free electrons that's why they are able to conduct electricity.. But I never understood why. Is that related to metallic ...
- 468
1
vote
3
answers
699
views
Why are non-metallic elements with partially filled valence bands not conductors?
Throughout this whole question, I will be referring solely to single element solids. According to band theory, ns and np bands are close enough in energy to overlap and create one band with 8N states ...
- 21
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
3
votes
4
answers
3k
views
In metals, the conductivity decreases with increasing temperature?
I am currently studying Principles of Optics: Electromagnetic Theory of Propagation, Interference and Diffraction of Light, 7th edition, by Max Born and Emil Wolf. Chapter 1.1.2 Material equations ...
- 889
1
vote
1
answer
94
views
Does the electron in wire too move because of voltage difference?
When we talk about electricity through a circuit because of a battery it is said that the electrons from negative terminal travel to positive terminal of the battery.
I can't help but imagine about ...
- 300
0
votes
0
answers
26
views
What causes the charges in conductor to move towards lower potential terminal of cell [duplicate]
Whenever a conductor is connected to a cell,what causes the conventional positivecharges inside it to move towards the lower potential level of cell..
My question is whether the charges experience a ...
- 31
1
vote
1
answer
53
views
Is it necessary that a capacitor stores charge?
Is it necessary that a capacitor storage charge? I am a little bit confused.
For example: if I take two concentric conducting shells and a positive point charge at the centre. Both the surfaces (outer ...
- 99
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-...
1
vote
1
answer
130
views
Why electric field not coming out of a conductor when current flows?
Why electric field not coming out of a conductor?
With the knowledge of High school physics, I assumed that I have learned following regarding Electric Current.
Current is moving charge and defined ...
- 11
1
vote
1
answer
565
views
Can a conductor be uniformly charged?
I have been reading in books that charges on a conductor resides on its surface and that for a body to be uniformly charged it has to be an insulator.Is it true?If yes does it mean we can consider a ...
0
votes
1
answer
121
views
When AC electricity is generated, how does the current flow? [duplicate]
I have read multiple different versions of how AC current flows in our power lines. How does the current flow? Is the energy just photonics waves passing through electrons that vibrate or are ...
- 1
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
2
votes
1
answer
362
views
How does electricity work exactly? [closed]
So it just isn't popping for me how electricity actually works.
AC at 60 Hz can swap directions 60 times a second and drift at roughly 1 m/s while they kind of ping pong forward with constant push ...
1
vote
1
answer
503
views
Can metal or carbon vapour conduct electricity?
Not a duplicate of Can Gases conduct Electricity, since it asks about ionised gases, which is irrelevant to my question.
This is what I already know:
All metals have a giant metal lattice, where ...
- 148
0
votes
4
answers
2k
views
Charge on hollow spherical surface
Let a point charge $+Q$ is placed in center of hollow spherical conductor of inner radius $a$ and outer surface $b$. Then the charge on the inner surface of radius $a$ is $-Q$ and outermost surface ...
- 135