Electromagnetic induction between 2 coils problem.

In summary, the conversation discusses the relationship between induction and frequency, with higher frequencies resulting in a more intense induction effect. It is noted that there is no induction in the case of DC current flow, as DC corresponds to a frequency of 0. The conversation also touches on the effects of high frequencies and the relevance of the speed of light. The conversation ends with a discussion on the practicality of building transformers and the limitations of induction at larger distances.
  • #1
aditya23456
114
0
We know that
1)a change in current and voltage in a coil may result in induction in other stationary coil..this induction is directly related to frequency..ie The higher the frequency the more intense the induction effect.
2)we also know that there is no induction in case of DC current flow..
considering frequency to be infinite,we have a DC current flow and at same time we need to observe very high induction as per (1)..therefore where am I wrong.??
 
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  • #2
DC corresponds to a frequency of 0, not an "infinite frequency".

The higher the frequency the more intense the induction effect.
Depends on the setup and the definition of "intense".
 
  • #3
then what does frequency tending to infinite correspond to..? Is it anything which is not defined..
Intense defined as magnitude of field induced
 
  • #4
I don't think there is a meaningful way to describe something as "infinite frequency". You can look how induction works for very high frequencies, but not for an infinite frequeny. In addition, you get many new effects if the speed of light becomes relevant.
 
  • #5
really thanks for info..I was reading abt telsa's wireless power transmission where i came across this..He used high frequency alternator for his tesla coil..I was wondering extreme case of this high frequency..I dint understand your last statement..did you mean speed of light relevant to frequency resulting in negligible wavelength..??what effects take place..?
 
  • #6
In usual AC setups, you can assume that everything is in an equilibrium - the changes of current and voltage are small within the time electromagnetic fields need to propagate through your setup (about 1 nanosecond for 30cm, the speed of light). If that assumption is wrong, things can get tricky. A coil with 30cm diameter is not useful to convert GHz-signals (1 nanosecond per cycle), for example.
 
  • #7
eletromagnetic induction occurs via electromagentic waves...light is the visible portion
of these waves...in many common inductions, like those of small coils at 60Hz, the speed of propagation...that is, the speed of light... is immaterial...but at ultrahi frequencies and large coils or large coil separation, such time delay of propagation may have to be taken
into account.
all this is what mfb is taking about.
 
  • #8
what are these effects basically.? These effects can be found even at low(not highly low) frequency changes,,taking the other coil to be far enough..isn't it.?? Then we can find these effects to a coil near you,getting effected from some other inducing coil which is far enough for frequency to be comparible to time of propagation and magnitude being high enough that it can make necessary induction
 
  • #9
You cannot build a transformer with a size of ~5000km (for 50 or 60 Hz). Everything beyond ~10m is impractical, and that corresponds to frequencies in the upper MHz range.
 
  • #10
Replying to post #8: if I understand your points, 'yes'...to them all.
 

FAQ: Electromagnetic induction between 2 coils problem.

1. What is electromagnetic induction?

Electromagnetic induction is the process by which a changing magnetic field induces an electric current in a conductor.

2. How does electromagnetic induction occur between two coils?

When a current flows through one coil, it creates a magnetic field around it. This changing magnetic field then induces an electric current in the nearby coil, as predicted by Faraday's Law of Induction.

3. What factors affect the strength of the induced current?

The strength of the induced current depends on the rate of change of the magnetic field, the number of turns in the coils, and the distance between the coils.

4. Is the direction of the induced current always the same?

No, the direction of the induced current depends on the direction of the changing magnetic field and the orientation of the coils. It follows Lenz's Law, which states that the induced current will flow in a direction that opposes the change in magnetic field.

5. How is electromagnetic induction used in real-life applications?

Electromagnetic induction is used in a variety of applications, such as generators, transformers, and electric motors. It is also used in wireless charging and induction cooktops.

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