InterviewSolution
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InterviewSolution
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A current of `4.4A` is flowing in a copper wire of radius `1mm` density of copper is `9 xx 10^(3)kg m^(-3)`and its atoms is `63.5u` If every atoms of copper contributes one condition electron , then the drift velocity of electrons is nearly [density of copper `9 xx 10^(3) kg m^(3)]`A. `0.1mm s^(-1)`B. `0.5mm s^(-1)`C. `1mm s^(-1)`D. `1.5mm s^(-1)` |
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Answer» Correct Answer - a Atomic mass of copper `M = 63.5g = 0.0635 kg` No of copper atoms in `0.0635kg` coppere `= 6.02 xx 10^(23)` Density of copper `= (M)/(d) = (0.0635)/(9 xx 10^(3)) m^(3)` Total no of atoms in unit volume of copper `= (9 xx 10^(3))/(0.0635) xx 6.02 xx 10^(23) = 8.5 xx 10^(28) "atoms"//m^(-3)` As one atom of copper contributes one conduction electron to so the electron density of copper `n = 8.5 xx 10^(28)m^(-3)` Drift velocity`v_(d) = (1)/(n Ae)` `= (44)/((6.5 xx 10^(28)) xx pi(0.001)^(2) xx (1.6 xx 10^(-19))` `0.1 xx 10^(-3)m//s = 0.1mm//s` |
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