All Questions
141
questions
0
votes
2
answers
248
views
Does a battery in a vacuum produce a current?
I've always assumed that the strong resistance of air is the reason there is no flow of electrons between the terminals of a battery until a wire is connect. However, in a vacuum there is no resistive ...
8
votes
9
answers
6k
views
Why does electricity need wires to flow?
If you drop a really heavy ball the ball's gravitational potential energy will turn into kinetic energy.
If you place the same ball in the pool, the ball will still fall. A lot of kinetic energy will ...
- 2,009
1
vote
2
answers
665
views
Simple ohms law on a battery ? Paradox or conceptual error?
Suppose we have a regular pencil battery which supplies DC voltage $V$. Say we take copper wire and connect the ends of the battery to an $R$ ohms resistance.
Then Ohm's law tells use the current in ...
- 501
2
votes
2
answers
2k
views
Under what condition charges do not flow in closed circuit?
I wanted to ask under what conditions will charges not flow in a closed circuit. Or when is current through the circuit zero even when an EMF is applied?
Like in the case of potentiometer, we say that ...
- 357
6
votes
2
answers
7k
views
How to calculate required current and specifications for a "wet coil" to generate x Tesla of magnetic field?
A water management project requires a "wet coil" (coil will be submerged in aqueous media) designed to generate a steady-state electromagnetic field of adjustable magnetic magnetic flux density at the ...
- 163
2
votes
0
answers
817
views
Skin effect and currents
Here in this picture
you can see $I_W$ which is induced by H.
But why $I_W$ is not vice versa?
Because of
$$rot \, \vec B = \mu_0 \, \left( \varepsilon_0 \frac{\partial \vec{E}}{\partial t} + \vec j \...
- 919