Related InterviewSolutions

• Which of the following statements concerning the depletion zone of an unbiased p-n junction is (are) true?A. The width of the zone is independent of the densities of the dopants (impurities).B. The widthof the zone is dependent on the densities of the dopantsC. The electric field in the zone is produced by ionised dopant atomsD. The electric field in the zone is provided by electrons in the conduction band and the holes in the valence band
• If a semiconductor has an intrinsic carrier concentration of `1.41 xx 10^(16)//m^(3)` when doped with `10^(21)//m^(3)` at room temperature will beA. `2 xx 10^(21)`B. `2 xx 10^(11)`C. `1.41 xx 10^(10)`D. `1.41 xx 10^(16)`
• In a `n`-type semiconductor, which of the following statement is true?A. Electrons are majority charge carriers and triavalent atoms are the dopants.B. Electrons are minority charge carriers and pentavaent atoms are the dopants.C. Holes are minority charge carriers and pentavalent atoms are the dopantsD. Holes are majority carriers and trivalent atoms are the dopants.
• The conductivity of a semiconductor increases with increase in temperature becauseA. Number density of free current carries increasesB. relaxation time increasesC. both number density of carriers and relaxation time increasesD. number density of current carriers increases, relaxation time decreases but effect of decreases in relaxation time is much less than increase in number density.
• If the resistivity of copper is `1.7 xx 10^(-6) Omega cm`, then the mobility of electrons in copper, if each atom of copper contributes one free electron for conduction, is [The amomic weight of copper is `63.54` and its density is `8.96 g//c c]` :A. 23.36 `cm^(2)`/VsB. 503.03 `cm^(2)`/VsC. 43.25 `cm^(2)`/VsD. 88 `cm^(2)`/Vs
• A transistor is preferable to a triode valve when used in amplifier because it i) Can withstand large changes in tempratures ii) has a higher input impedance iii)can handle larger powers (iv) does not require powers Which of the above statements is correct?A. Only (i), (ii), and (iii) are correctB. Only (i), and (iii) are correctC. Only (ii) and (iv) are correctD. Only (vi) is correct.
• What is the plate current in a diode valve under the space charge limited operation, when the plate potential is 60 V? In a diode valve, the plate current is 320 mA, then the plate potential is 240 V.A. 30 mAB. 20 mAC. 40 mAD. 10 mA
• When the plate voltage of a triode is 150 V, its cut-ff voltage is `-5V`. On increasing the plate voltate to 200V, the cut-off voltage can beA. `-4.5`VB. `-5.0`VC. 2.3 VD. `-6.66 V`
• In a triode amplifier, the load resistance is equal to the plate resistance `r_(p)`. If `mu` is the amplification factor, the stage gain of the amplifier isA. `(mu)/2`B. `mu`C. `2mu`D. `(mu)/4`
• In BJT, maximum current flows in which of the following?A. Emitter regionB. Base regionC. Collector regionD. Equal in all the regions