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A copper wire has a resistance of 10Omega and an area of cross-section 1 m m^(2). A potential difference of 10 V exists across the wire. Calculate the drift speed of electrons if the number of electrons per cubic metre in copper is 8xx10^(28) electrons. |
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Answer» Solution :Here, `R=10Omega, A=1 mm^(2)=10^(-6)m^(2), V=10V, n=8xx10^(28)"electrons/m"^(3)` Now, `I=enAv_(d)` `therefore (V)/(R )=enAv_(d)"" (or) v_(d)=(V)/(enAR)` `=(10)/(1.6xx10^(-19)xx8xx10^(28)xx10^(-6)xx10)=0.078xx10^(-3)ms^(-1)` `=0.078xx m ms^(-1)` |
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