1.

What is so special about the combination e/m ? Why do we not simply talk of e and m separately ?

Answer»

Solution :When we study energy of electron ACCELERATED by an accelerating voltage V, then we find that
`K=(1)/(2)mv^(2)=eV implies v^(2)=(2e)/(m)V` . . (i)
When we study MOTION of an electron beam ALONG an electric FIELD `vecE`, we find that
`vecF=-evecE=mveca`
or Acceleration of electron `veca=-(e)/(m)vecE`. . (ii)
Again when consider motion of an electron beam in a magnetic field acting normally, the radius of electron path is given by `r=(mv)/(eB)`. . . . (iii) All the three relations given above and many more such relations show that dynamics of electrons is governed by its specific charge `((e)/(m))`.


Discussion

No Comment Found

Related InterviewSolutions