All Questions
17
questions
1
vote
2
answers
28
views
Question Regarding The Movement of Charges [duplicate]
We know that two electrons repel each other since they have like charges, which means they move in opposite directions. But how can they move if they exert equal and opposite charges, aren't the ...
- 11
0
votes
1
answer
173
views
How is Lorentz Force $BQv=BIl$?
The formula for Lorentz Force on moving charge is $$F=BQv$$ which for current carrying wire is modified to $$F=BQv$$$$=BQ\frac lt$$$$=BIl$$
Where $l$ is the length of the wire inside the magnetic ...
- 1,168
0
votes
2
answers
2k
views
Will solenoid expansion take place when current is flowing though it?
I came across this when doing my revision exam paper and had this doubt. I wanted to ask whether a solenoid will expand radially outwards when current flows through it.
(The actual question was ...
- 79
0
votes
2
answers
187
views
Electromagnetic force at a distance
Is it possible for an electromagnet of around 50mm diameter to produce a force of 1000N at 10mm distance far away ferromagnetic object (air between them) ? If yes, how much power (approx) will it need ...
- 19
0
votes
1
answer
64
views
Magnetic force on a stationary body
A charged particle near a current-carrying wire does not experience a magnetic force when its velocity is equal to $0$. So why does a compass needle kept near a current carrying wire experience a ...
1
vote
0
answers
60
views
What should be the equilibrium field strength in the Hall effect?
I was taught in my course and have confirmed by looking in many sources that when there are moving charges (e.g. current in a wire) which are deflected due to the Lorentz force (Hall effect), the ...
0
votes
1
answer
58
views
Why astatic needles are immune to only terrestrial magnetic fields and not other magnetic fields?
This web article says:
Astatic needles are basically two needles of approximately the same magnetic strength, mounted on top of one another. They are parallel, but their magnetic poles are on ...
- 137
0
votes
1
answer
451
views
Forces between current carrying wires [closed]
Why the wires bearing current in the same direction don't attract to each other?
- 17
0
votes
0
answers
23
views
Why does linear motion not affect the reading on a hall probe?
Moving the hall probe forward at velocity v would make all the electrons in it propel at velocity v, so the magnetic force on each electron (qV x B ) would increase. If so, unless there's some fuzzy ...
- 254
0
votes
2
answers
702
views
How paper strips get electrified?
Why paper strips get electrified when we iron them? I have learned that when two insulators are rubbed then they gets electrified but in case of ironing a paper the iron is a conductor. Will rubbing a ...
- 524
2
votes
2
answers
4k
views
Force on a magnetic dipole due to a magnetic field
Imagine a solenoid which has current $i$ and is producing a magnetic field $B$ which equals $$B=\mu N i$$
Now, imagine we put a small cylindrical magnet at the end of the solenoid.
Then because at ...
- 322
0
votes
1
answer
219
views
Could someone simply explain how a railgun works?
Could someone simply explain how a railgun works? What could possibly accelerate an object that fast in such a short distance? I've heard it has to do with current between two rails, but I simply do ...
- 221
15
votes
9
answers
9k
views
How do electrons know when a circuit is closed?
I was told that electrons do not begin flowing unless the circuit is closed. The electrons from the battery are not in the ends of wire when it is open, apparently, as there is no reason for them to ...
- 221
1
vote
4
answers
12k
views
Why do like charges repel and opposite charges attract? [duplicate]
Why do like charges repel and opposite charges attract?
0
votes
1
answer
829
views
Understanding the relationship between electric energy and force
I'm trying to do the following problem:
One of the three types of radioactive decay is "β decay", during which protons decay into neutrons or viceversa, emitting either electrons (β) or positrons (...
- 125