8
votes
Can a satellite generate electricity by using a planet's magnetic field?
The Earth's magnetic field is very weak compared to that produced by a magnet you might '[slide] next to a coil' and the time over which the field will vary is long (> ~90 minutes for one orbit), ...
- 2,976
3
votes
Ampere's law on solenoid, using a circular loop
So, you're just doing:
$$ \epsilon \rightarrow 0 $$
but never getting there, and then asking:
"Hey, why is $\epsilon \ne 0$"
The field outside the solenoid is not zero, it is only zero if:
...
- 35.4k
2
votes
Accepted
Isn't the induced electric field vector always tangent to the loop?
But isn't the field $\mathbf E$ which is responsible for the induced emf also along the contour (unit tangent vector $\hat{\mathbf t}$)?
No, the equation is true for any contour you choose in a given ...
- 28.1k
2
votes
Accepted
Can plasmas have eddy currents?
Yes. Induced currents in plasmas can be useful. The poloidal field in a tokamak is an eddy current induced by a magnetic field that threads the torus.
- 21.8k
1
vote
How is a steady current maintained in case of motional EMF if net force on electrons is zero?
if they are slowed down or are sent in random directions once they encounter resistance in the wire then how should a steady current keep flowing?
If the rod is isolated, only then electric charge ...
- 39k
1
vote
How is a steady current maintained in case of motional EMF if net force on electrons is zero?
Indeed there is no current in the rod once the force on the electrons become zero.
While the rod was entering in the magnetic field , the magnetic force acted on the free electrons to produce a ...
- 378
1
vote
Accepted
How does the induced current flow? From positive to negative or the opposite?
This situation is easier to understand when you can see a circuit. In many examples like yours, involving a rod moving in a magnetic field, the circuit is completed by having the rod move along fixed ...
- 1,884
1
vote
Isn't the induced electric field vector always tangent to the loop?
Do you mean "which is responsible" or "that is responsible"?
(See Strunk and White, Which Hunts: https://clubtroppo.com.au/2008/11/30/the-great-which-hunt/).
The former is ...
- 35.4k
1
vote
Straight wire in moving uniform magnetic field induced emf
First : scenario 1 and two are not the same in scenario 2 B moves relative to the full loop not only relative to the green rod, so there will not be any emf induced, same as if moving the whole loop ...
- 6,362
1
vote
Cannot catch a minus sign mistake when deriving the ODE for an LC circuit
You're using opposite sign conventions for the potential differences across the capacitor and the inductor.
Arbitrarily designate one terminal of the capacitor as $C_{in}$ and the other one as $C_{out}...
- 1,255
Only top scored, non community-wiki answers of a minimum length are eligible