1
GATE ECE 2015 Set 2
Numerical
+1
-0
An n–type silicon sample is uniformly illuminated with light which generates 1020 electron hole pairs per cm3 per second. The minority carrier lifetime in the sample is 1 $$\mathrm\mu$$s.In the steady state, the hole concentration in the sample is approximately 10x , where x is an integer. The value of x is __________________
2
GATE ECE 2015 Set 2
Numerical
+1
-0
A piece of silicon is doped uniformly with phosphorous with a doping concentration of $$10^{16}/cm^2$$. The expected value of mobility versus doping concentration for silicon assuming full dopant ionization is shown below. The charge of an electron is $$1.6\;\times\;10^{-19}\;C$$. The conductivity (in S cm-1) of the silicon sample at 300 K is _________________. 3
GATE ECE 2015 Set 1
Numerical
+1
-0
A silicon sample is uniformly doped with donor type impurities with a concentration of $$10^{16}/cm^3$$.The electron and hole mobilities in the sample are $$1200\;cm^2/V-s$$ and $$400\;cm^2/V-s$$ respectively. Assume complete ionization of impurities. The charge of an electron is $$1.6\;\times\;10^{-19}\;C$$.The resistivity of the sample $$\left(in\;\Omega-cm\right)$$ is _____________.
4
GATE ECE 2014 Set 4
+1
-0.3
In the figure ln(ρi) is plotted as a function of 1/T, where ρi the intrinsic resistivity of silicon, T is is the temperature, and the plot is almost linear. The slope of the line can be used to estimate

A
Band gap energy of silicon (Eg)
B
Sum of electron and hole mobility in silicon $$\left(\mu_n+\mu_p\right)$$
C
Reciprocal of the sum of electron and hole mobility in silicon $$\left(\mu_n+\mu_p\right)^{-1}$$
D
Intrinsic carrier concentration of silicon (ni)
GATE ECE Subjects
Network Theory
Control Systems
Electronic Devices and VLSI
Analog Circuits
Digital Circuits
Microprocessors
Signals and Systems
Communications
Electromagnetics
General Aptitude
Engineering Mathematics
EXAM MAP
Joint Entrance Examination