All Questions
41
questions
0
votes
1
answer
38
views
Force on charge carriers in a simple circuit
Is it true that in a simple circuit where a simple conducting wire is connected to a battery, the force on each charge carrier is same in magnitude ? If yes, then can you explain how? I know that if ...
1
vote
2
answers
123
views
Why does the power loss in transmission cable increase when resistance is increased?
In transmission cables, why does power loss increase when length of conductor is increased? According to the formulas V=IR and P=I²R, When we increase the length, the resistance increases, while the ...
0
votes
1
answer
77
views
Why does the current flow through a wire if the wire is an equipotential surface? [duplicate]
From what I know, current flows across two points only if there is some potential difference across those two points. If that is the case, why does the current flow through a wire then?
See the ...
0
votes
2
answers
123
views
Current by change in position of charges
I have been thinking about the idea given below
Consider the following situation
I have a rod which has a mass $m$ and hence does have the virtue to perform work against the gravitational field of ...
0
votes
1
answer
33
views
Analysis of Current for infinitesimal time
Suppose we have a hydrogen atom and electron is revolving in a orbit around the nucleus. We have to find current due to the revolving electron.
Current = ev / 2πr
( e = charge of electron)
( v = ...
- 109
0
votes
1
answer
644
views
Why Do Van De Graaff Generators Only Shock When Grounding Someone?
When someone touchs the metal sphere of the Van De Graaff Generators, the charge on them builds up, causing the famous hair raising. However, why is it when a person is rapidly grounded by someone ...
- 101
0
votes
1
answer
19
views
Electrostatic attraction between charges in different media
Imagine you have two non-conducting spheres of density a (a < density of water). Therefore the spheres float on the surface of water with a portion of their bodies immersed in water. Now how do you ...
0
votes
1
answer
154
views
Would a grounded copper heat sink located near a room's ceiling be an effective way to reduce a room's temperature?
I am thinking about a cheap but effective way to reduce the temperature of my bedroom in my apartment during hot summer nights. I live in an old apartment building and the air conditioner located in ...
- 478
0
votes
1
answer
2k
views
Is it possible to convert static electricity into current electricity?
Generally, static electricity is created by friction between two or more different materials and it doesn't flow through a circuit.
On the other hand, current electricity is the flow of electrons ...
- 1,070
0
votes
3
answers
100
views
What is the definition of direction of current?
Wikipedia defines the direction of current as:
The direction of conventional current is arbitrarily defined as the direction in which positive charges flow.
But suppose a region where there is a non-...
- 480
1
vote
1
answer
303
views
Potential difference between two hollow spheres and amount of current flow
If two Hollow Spheres with radius $r_1$ and $r_2$ have charge $q_1$ and $-q_2$ in them respectively(charges are evenly distributed in the surfaces).The spheres are separated by a distance d .Now We ...
- 27
-1
votes
3
answers
1k
views
If the earth is negatively charged why is lightning striking it?
So, as far as I know, the Earth is negatively charged, and there are such things as lightning strikes which travel from clouds to the Earth- that would mean the clouds in a thunderstorm are positively ...
- 109
0
votes
1
answer
43
views
Can current due to potential difference of earth's crust and ionosphere charge objects?
A man fixes outside his house one evening a two metre high insulating slab carrying on its top a large aluminium sheet of area $m^2$ . Will he get an electric shock if he touches the metal sheet next ...
2
votes
2
answers
169
views
Confusion over Van de Graaff vs. Electric Fence
It is said "It is not the volts that kill you, but rather the current".
However, volts is directly related to current as V= IR (current x resistance).
Since the resistance of one particular ...
- 45
0
votes
2
answers
95
views
Can someone please explain the difference between an electric charge and electric current? [closed]
Well I understand the definition my question was that we measure charge by calculating 6.24 *10 powers 28 in one second then what is electricity if it is the rate of flow of charge is,t it's the same ...
- 11
4
votes
2
answers
1k
views
Does current flow in the wire when only one terminal of the battery is earthed?
Let me specify beforehand that this question has been asked previously but I haven't been able to satisfy my curiosity.I know a battery maintains a potential difference between it's terminals , let's ...
- 1,103
3
votes
3
answers
4k
views
Grounding on the wooden floor
Let's suppose that I'm touching a live wire and standing on a wooden floor. Will I be shocked? Or e.g. standing in a plastic tub filled with water. I cannot imagine that there is a closed circle to ...
- 51
0
votes
2
answers
219
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 ...
3
votes
5
answers
2k
views
Basic question about electric shock
When we are negatively charged, and we touch a doorknob for example, why does the shock happen (i.e. the flow of charge)?
I understand that the electrons want to flow to positive charges, and I know ...
- 39
-1
votes
2
answers
144
views
Is my understanding of current correct?Urgent help is needed! [closed]
I had asked this question:No matter the arrangement of resistors in a circuit, a battery will still produce a current as if it were connected to an imaginary combination of the individual resistors ...
- 1,235
1
vote
1
answer
7k
views
Why is the drift velocity directly proportional to the electric field?
If I double the electric field, that should double the acceleration of electrons inside the conductor in the general direction of the electric field. But why does that double the drift velocity, and ...
- 3,075
2
votes
1
answer
170
views
Open current loops in metal conductor
Hello everyone,
I have this question, "can Ac current flow in an open circuit ?", I give the example of a coil carrying an AC current placed above a conducting surface, since we have an AC current, ...
- 130
1
vote
1
answer
181
views
Would a metal chair suspended in air be hit by lightning or not?
I was reading "The Physics of Superheroes" by James Kakalios and I came across the following paragraph:
In one scene during their climatic battle, Spider-Man manages to
deflect an electrical bolt ...
- 357
1
vote
0
answers
129
views
Conductivity and free/bound charge for conductors, insulators/dielectrics and semiconductors
I am slightly confused about the distinction between these three types of material in terms of
a) conductivity
b) the idea of free and bound charge
If we consider the distinction between these in ...
- 3,997
0
votes
2
answers
2k
views
In which terminal does current starts to flow first i.e. positive or negative?
As current(DC) flows from positive to negative terminal which is actually flow of electrons which in turn flow from negative to positive terminal.
So the question is which side of battery starts ...
- 115
0
votes
3
answers
64
views
What is the minimum safe distance a human finger can be placed away from a live contact of 16A, 250V? [closed]
what is the minimum safe distance a human finger can be placed away from a live contact of 16A, 250V and not get shock. Would this distance change if the air was humid?
Would this distance change if ...
-1
votes
1
answer
142
views
Neutralizing The Earth's Charge
The Earth's surface has a negative surface charge density of $1/10^9\,\mathrm{C/m}^2$. The potential difference of $400\,\mathrm{kV}$ between the top of the atmosphere and the surface results in a ...
- 290
0
votes
1
answer
771
views
Condition for Maximum Power in the circuit [duplicate]
Maximum Power is transferred to a load when load resistance is equal to internal resistance of source.
I want to know How ?
If I consider a source with internal resistance 'R' ,connected with ...
- 293
0
votes
2
answers
360
views
Why does $dq = \lambda (t+dt)dz - \lambda (t)dz = d\lambda dz$?
I am having trouble understanding why $$\frac{dq}{dt} = I(z) - I(z+dz) = -dI dz.$$
The question: There is an infinite wire along the z-direction. The current in the wire depends on $z$, and the ...
- 741
4
votes
7
answers
34k
views
What is the difference between conventional current and electronic current?
what is the difference between conventional current and electronic current?
How are they linked to one another?
