The mean free path of electrons in a metal is 4 10-8 m. The electric field which can give on an average 2 eV energy to an electron in the metal will be in units V/m
(3) 5 107
Energy gained by the electron over one mean free path :
eE = 2 eV
E = 2 V = 24 10-8
E = 5 107 V/m
Answer: (3)
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