An electron has an intrinsic angular momentum (spin) whose component in an arbitrary direction is one half of the Planck's constant, i.e. L_2=h//2=5.25xx10^(-35) J .s. Making use of the fact that the speed of light in vacuum is the maximum attainable, prove that a model in which the spin of an electron is due to the rotation about its axis is not feasible.

An electron has an intrinsic angular momentum (spin) whose component i

1.	An electron has an intrinsic angular momentum (spin) whose component in an arbitrary direction is one half of the Planck's constant, i.e. L_2=h//2=5.25xx10^(-35) J .s. Making use of the fact that the speed of light in vacuum is the maximum attainable, prove that a model in which the spin of an electron is due to the rotation about its axis is not feasible.
Answer» Solution :The moment of the ball.s momentum is `L = Iomega = 2/(5)mr^2v/r=2/5` mvr ,where v is the orbital VELOCITY on the equator. SINCE `v ltc, L lt2/5` , whence `rgt(5L)/(2mc) , "or " r gt (5h)/(4 mc)=4.8 xx10^(-13)m` This dimension does not agree with experimental data, according to which the effective electron radius is two orders of magnitude less.

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