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Find the relaxation time for free electr...

Find the relaxation time for free electrons in copper, if the density of mobile electrons in copper, if the density of mobile electrons is `8.4 xx10^(28) m^(-3)`. The resistivity of copper at room temperature is `1.7xx10^(-8)Omega m`.
Given : mass of electron `=9.11 xx10^(-31) kg ` and charge on electron `=1.6xx10^(-19)C`.

A

`2.49 xx 10^(-14)` second

B

`1.9 xx 10^(-8)` second

C

`2.49 xx 10^(14)` second

D

none

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The correct Answer is:
A
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Find the relaxation time for free electrons in copper, if the density of mobile electrons is 8.4 xx10^(28) m^(-3) . The resistivity of copper at room temperature is 1.7xx10^(-8)Omega m . Given : mass of electron =9.11 xx10^(-31) kg and charge on electron =1.6xx10^(-19)C .

If the free electron density of copper is 8.6xx10^(28)m^(-3) and resistivity of copper at room temperature is 1.7xx10^(-6)Omega cm , find the relaxation time for the free electrons of copper. Given, mass of electron =9.1xx10^(-31) kg , and charge of electron =1.6xx10^(-19)C .

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Calculate the relaxation time and mean free path at room temperature (i.e. 27^(@)C ). If the number of free electrons per unit volume is 8.5 xx 10^(28)//m^(3) and resistivity rho = 1.7 xx 10^(8) Omega-m . Given that mass of electron = 9.1 xx 10^(-31) kg e = 1.6 xx 10^(-19)C and k = 1 .36 xx 10^(-23) JK^(-1)

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Find the time of relation between collision and free path of electrons in copper at room temperature .Given resistance of copper = 1.5xx 10^(-8) Omega m number density of electron in copper = 8.5 xx 10^(28)m^(-3) charge on electron = 1.6 xx 10^(19)C , mass of electrons = 9.1 xx 10^(-19) kg Drift velocity of free electron = 1.6 xx 10^(-4)ms^(-1)

Electron density in a copper wire is 8.0 xx10^(22) cm ^(-3) . Calculate the relaxation time for electrons if the resistivity of copper is 1.68xx10^(-8) Omega m at room temperature. (Massof electron is 9.1 xx10^(-31) kg .)

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