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Q1 - Electronic Devices and Circuits
Electric field of $1\;V/m$ is applied to a Boron doped Silicon semiconductor slab having doping density of $10^{16}\;atoms/cm^3$ at $300K$ temperature. Determine the approximate resistivity of the slab.
(Consider intrinsic carrier concentration of Silicon at $300K\;=\;1.5×10^{10}/cm^3$ Hole mobility$=500\;cm^2/Vs$ at $300K$; Electron mobility $=1300cm/Vs$ at $300K$)
a) $0.48\;\Omega-cm$
b) $0.35\;\Omega-cm$
c) $0.16\;\Omega-cm$
d) $1.25\;\Omega-cm$
Correct Answer: Option B
Given:
Electric filed $E\;=\;1V/m$
Doping material = Boron (p-type)
Doping concentration $N_A=10^{16}\;atoms\cm^3$
Resistivity $\rho=?$
Solution:
Circuit theory - Basics - Q2
🌾How many electrons are there in one coulomb of electricity?
a) $6.023×10^{23}$
b) $1.64×10^{24}$Â
c) $6.24×10^{18}$Â
d) $1.602×10^{-19}$Â
Circuit theory - Basics - Q3
🌾Which of the following amount of electrons is equivalent to $-3.941\;C$ of charge?
a) $1.628×10^{20}$
b) $1.24×10^{18}$
c) $6.482×10^{17}$
d) $2.46×10^{19}$
Correct Answer: Option D
One coulomb of charge equals
$$-1C=6.24×10^{18}\;e^-$$
‘n’ coulombs of charge equals,$$-nC=n×6.24×10^{18}\;e^-$$
Hence, $-3.941\;C$ equals, $$=3.941×6.24×10^{18}\;e^-$$ $$=24.59×10^{18}\;e^-$$ $$=2.459×10^{19}\;e^-$$
Circuit theory - Basics - Q4
🌾Unit of a charge is
a) ampere-second
b)Â volt
c)Â coulomb
d)Â watt
Correct Answer: Option A and C
Unit of charge is coloumb.
Since $I=Q/t$ and $Q=It$, the unit of charge is also ampere-seconds
Circuit theory - Basics - Q5
Tamilnadu TRB $2006$ exam
🌾Which of the following equation is correct?
a) $I=Q×t$
b)Â $I=Q/t$
c)Â $Q=I/t$
d)Â None of these
Correct Answer: Option B
Current flow is nothing but the rate of flow of charge $$I=\frac{Q}{t}$$