Magnetic dipole moment of a revolving electron | video in HINDI | EduPoint

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96.7 هزار بار بازدید - 8 سال پیش - In this Physics video lecture
In this Physics video lecture we evaluated the magnetic dipole moment of a revolving electron from the known equation of the magnetic dipole moment of a current carrying circular loop which is equivalent to a bar magnet. The dipole moment of a circular loop carrying current is the dipole moment of a bar magnet which creates the same magnetic field around it as the current loop does.

We know that magnetic dipole moment of a current loop,
 M ⃗  = I A ⃗   ……….…………………..(1)
where, I is current in the loop and A is the area of the loop.

Click here to watch the video in which we derived the equation for the magnetic dipole moment of a current carrying circular loop :
Magnetic dipole moment of a current c...


Let the period of orbital motion of an electron be T. then the electron crosses any point on its orbit after every T seconds or 1/T  times in one second. Therefore, the equivalent current due to the orbital motion of the electron is,
 I   =    - e  1/T     ….…………………..(2)
Now, if r is the radius of the path of the electron and v be its speed,
 T  =     2πr/v    ………………………….(3)
From  eqn (2) and eqn (3) we have,
 
 I   =    - e   v/2πr      …………………….(4)

Putting the value of I from  eqn (4) to eqn (1) we have,
 M =   - e   v/2πr  A
Or, M =   - e   v/2πr   πr^2  
Or, M =   -   (e v r)/2   …………………….(5)
We know that angular momentum of an electron,
 L   =    m_e v r        ………………….(6)
where, m_e is the mass of an electron.

From  eqn (5) and eqn (6) we have,
M  =   -   e/(2 m_e ) L  
In vector notation,
 M ⃗   =   -   e/(2 m_e ) L ⃗  


This Hindi video tutorial on the topic of Magnetism is very helpful for class 12 students and IIT JEE aspirants.



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8 سال پیش در تاریخ 1395/10/09 منتشر شده است.
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