A sample of germanium is doped to the extent of `10^(14)` donor atoms per `cm^(3)` and `7xx10^(13)` acceptor atoms per `cm^(3)`. The resistivity of pure germanium at the temperature of the sample is `60Omegacm`. Find the total conduction current density due to an applied electric field of `2Vcm^(-1)`. The electrom and hole mobilities are given to be `3800cm^(2)V^(-1)s^(-1)` and `1800cm^(2)V^(-1)s^(-1)`, respectivele.
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A chalk sample exactly 17.52 gram HCl for complete reaction with all `CaCO_(3)` present in it. If the chalk sample is 72% pure, the mass of sample tak
`CaCO_(3) + 2HCl to CaCl_(2) + H_(2)O+CO_(2)` Moles of HCl `=(17.52)/(36.5)` Moles of `CaCo_(3)=(1)/(2)xx(17.52)/(36.5)` Weight of `CaCO_(3)` required `=(1)/(2)xx(17.52)/(36.5)xx100` Mass of sample taken: `=(1)/(2) xx(17.52)/(36.5)xx(100xx100)/(72)=33.33` gm
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Electrons in a sample of H-atoms make transition from state n = y to some lower excited state. The emission spectrum from the sample is found to conta
Correct Answer - 8 `(3)/(4)xx0.85ev=13.6xx1^(2)[(1)/(n^(2))-(1)/(y^(2))]" "thereforen=4,y=8`
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(a) What change occurs when AgCl is doped with `CdCl_(2)` ? (b) What type of semiconductor is produced when silicon is doped with boron?
(a) `CdCl_(2)` on adding to AgCl introduces impurity defect. The addition of one `Cd^(2+)` ion will replace two `Ag^(+)` ions to maintain electrical conductivity. One of the position of `Ag^(+)`...
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Determine the number density of donor atoms which have to be added to an intrinsic germanium to produce an `n`-type semiconductor of conductity `0.06S
Correct Answer - `96x10^(16)m^(-3)`
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Germanium is doped one part million with indium at room temperature. Calculate the conductivity of doped germanium. Given: concentration of Ge atoms `
Correct Answer - `1.34xx10^(3)ohm^(-1)m^(-1)`
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Determine the conductivity and resistivity of pure germanium at `300K` assuming that at this temperature the concentration of germanium is `2.5xx10^(1
Correct Answer - `2.12Sm^(-1),0.472Omegam`
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The resistivity of pure germanium at a particular temperature is `0.52Omegam`. If the material is doped with `10^(20)` atoms `m^(-3)` of a trivalent i
Correct Answer - `0.195Omegam`
2 Answers 8 views
Calculate the electric field in a copper wire of cross-sectional area `2.0 mm^(2)` carrying a current of 1 A. The resistivity of copper `=1.7xx10^(-8)
Correct Answer - `0.85xx10^(-2) Vm^(-1)`
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Find the time of relaxation between collsion and free path of electrons in copper at room temperature. Given resistivity of copper`=1.7xx10^(-8) Omega
Correct Answer - `2.5xx10^(-14)s, 4.0xx10^(-8) m`
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A student added few drops of universal indicator to a given colourless sample and observed the sample turning to red. The nature of sample is
Correct option is B) acid
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