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Light of wave length 2480Å is incident on barium. Photoelectrons emitted from the surface of barium describe a circle of radius 100cm in a magnetic field of flux density (1)/(sqrt(17))xx10^(-5)T. Find the work function of barium. (given e/m =1.7xx10^(11) C/Kg ) |
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Answer» Solution :K.E of electron, `K=(e^(2)B^(2)R^(2))/(2m)` `K=((e)/(m))(eB^(2)r^(2))/(2)=8xx10^(-20)J=0.5eV` WORK funtion `W=E-K_(max)=(12400)/(2480)-0.5eV=4.5eV` |
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