iron rod linearly oscillating in d hollow core of a electromangnet

Replies

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  sanket_sali

  guys if you dont knw the answer plz tel so so that i may knw coz i came across diz efect while playing with the electromagnet i wanna knw is it a new invention r its just another coincidence so plzz co operate guys talk to me
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  Ramani Aswath

  I do not know what you mean by linear oscillation.
  Assume that you have solenoid coil with a hollow cylindrical central tube. Let the axis be vertical. Apply a suitable DC. You now have an electromagnet. If an iron rod is introduced into the coil slowly it will get pulled up and remain inside the coil stationary at an equilibrium position provided the current is sufficient to hold the weight of the rod.
  Now if the rod is pulled down, one can feel the upward tug as the solenoid is trying to pull in the rod to the original position. If the rod is released now, it will bob up and down like a pendulum. Ultimately the oscillations will be dampened and the rod will reach the original equilibrium position. This is rather like the oscillations of a weight at the end of a spring. If pulled and released, very similar oscillations result.
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  sanket_sali

  yes im talking about the same thing bt im not geting any damping in this d coil is geting heted n this process goes on even if you make the axis horizontal the coil gets heated bt d oscilations are not stoping or decreasing dey are continuosly varying like sometimes they increase in amplitude sometimes they decrease
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  Ramani Aswath

  Try applying a constant current DC. Coil heating is normal. Is the iron soft iron? Or has it become magnetized?
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  sanket_sali

  i used a constant current dc only the one we use for charging our phones 5 v 2000 ma source d charger adapter
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  sanket_sali

  rod is soft iron(i suppose) n is not magnetized
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  Ramani Aswath

  Those are simple chargers and are not constant current. If the weight of the rod, the dimensions of the solenoid and the energising current are all at some resonant values it is possible that you have long lasting oscillations.
  However, I am surprised that you are not seeing any damping. The amplitude variations are almost certainly due to variations in current. The oscillations of the rod itself will change the coil chracteristics to some extent. The phone charger cannot compensate for this.
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  sanket_sali

  its not actualy a phone charger bt wht device charger it is i dnt knw its a 5 v 2000ma charger is it not sufficent n do u think diz is smthin new n i shuld wrk on it or its vry common n nthing new in that
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  sanket_sali

  if you want i can mail u the video of the solenoid n that rod shall i so that you can see it yourself
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  Ramani Aswath

  As I said in the beginning it is quite similar to weighted spring oscillations. It is a harmonic oscillator.
  The spring version can be seen here:
  Harmonic Oscillator
  This paper gives some info:
  galileo.phys.virginia.edu/classes/317.gbh.fall05/mag.../Beams1.doc
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  Ramani Aswath

  sanket_sali

  if you want i can mail u the video of the solenoid n that rod shall i so that you can see it yourself

  Please do. It would be interesting.
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  sanket_sali

  done sir maild u the video in horizontal axis vertical axis is not that intresting you can imagin it easily diz one grabs my attension