1
GATE ECE 2014 Set 2
Numerical
+2
-0
Assume electronic charge q = 1.6×10-19 C, kT/q = 25 mV and electron mobility μn = 1000
cm2/V-s. If the concentration gradient of electrons injected into a P-type silicon sample is
1×1021/cm4, the magnitude of electron diffusion current density (in A/cm2) is _________.
Your input ____
2
GATE ECE 2010
MCQ (Single Correct Answer)
+2
-0.6
The silicon sample with unit cross-sectional area shown below is in thermal
equilibrium. The following information is given: T=300K, electronic charge=1.6x10-
19C, thermal voltage=26mV and electron mobility = 1350cm2/V-s

The magnitude of the electric field at x=0.5 μm is
3
GATE ECE 2010
MCQ (Single Correct Answer)
+2
-0.6
The silicon sample with unit cross-sectional area shown below is in thermal
equilibrium. The following information is given: T=300K, electronic charge=1.6x10-
19C, thermal voltage=26mV and electron mobility = 1350cm2/V-s

The magnitude of the electron drift current density at x=0.5 μm is
4
GATE ECE 2005
MCQ (Single Correct Answer)
+2
-0.6
A silicon sample 'A' is doped with 1018 atoms/cm3 of Boron. Another sample 'B' of
identical dimensions is doped with 1018 atoms/cm3 of Phosphorus. The ratio of
electron to hole mobility is 1/3. The ratio of conductivity of the sample A to B is
Questions Asked from Semiconductor Physics (Marks 2)
Number in Brackets after Paper Indicates No. of Questions
GATE ECE Subjects
Signals and Systems
Representation of Continuous Time Signal Fourier Series
Fourier Transform
Continuous Time Signal Laplace Transform
Discrete Time Signal Fourier Series Fourier Transform
Discrete Fourier Transform and Fast Fourier Transform
Discrete Time Signal Z Transform
Continuous Time Linear Invariant System
Discrete Time Linear Time Invariant Systems
Transmission of Signal Through Continuous Time LTI Systems
Sampling
Transmission of Signal Through Discrete Time Lti Systems
Miscellaneous
Network Theory
Control Systems
Digital Circuits
General Aptitude
Electronic Devices and VLSI
Analog Circuits
Engineering Mathematics
Microprocessors
Communications
Electromagnetics