1
GATE ECE 2016 Set 3
Numerical
+2
-0
The injected excess electron concentration profile in the base region of an npn BJT, biased in the
active region, is linear, as shown in the figure. If the area of the emitter-base junction is 0.001 cm2, µn = 800 cm2/(V-s) in the base region and depletion layer widths are negligible, then the collector
current Ic (in mA) at room temperature is __________.
(Given: thermal voltage VT = 26 mV at room temperature, electronic charge q = $$1.6\times10^{-19}\;C$$ )
Your input ____
2
GATE ECE 2015 Set 3
Numerical
+2
-0
An npn BJT having reverse saturation current $$I_s\;=\;10^{-15}\;A$$ is biased in the forward active
region with VBE = 700 mV. The thermal voltage (VT) is 25 mV and the current gain (β)
may vary from 50 to 150 due to manufacturing variations. The maximum emitter current
(in μA) is _____.
Your input ____
3
GATE ECE 2014 Set 4
Numerical
+2
-0
Consider two BJT's biased at the same collector current with area A1 = 0.2 μm × 0.2 μm and
A2 = 300 μm × 300 μm. Assuming that all other device parameters are identical, kT/q = 26
mV, the intrinsic carrier concentration is 1 × 1010 cm-3, and q = 1.6 × 10-19 C, the difference
between the base-emitter voltages (in mV) of the two BJT's (i.e., VBE1 – VBE2) is___________.
Your input ____
4
GATE ECE 2011
MCQ (Single Correct Answer)
+2
-0.6
The channel resistance of an N-channel JFET shown in the figure below is 600 W
when the full channel thickness (tch) of 10 μm is available for conduction. The
built-in voltage of the gate P+N junction (Vbi) is -1 V. When the gate to source
voltage (VGS) is 0 V, the channel is depleted by 1 μm on each side due to the built in
voltage and hence the thickness available for conduction is only 8 μm
The channel resistance when VGS = 0 V is
Questions Asked from BJT and FET (Marks 2)
Number in Brackets after Paper Indicates No. of Questions
GATE ECE Subjects
Network Theory
Control Systems
Electronic Devices and VLSI
Analog Circuits
Digital Circuits
Microprocessors
Signals and Systems
Representation of Continuous Time Signal Fourier Series Discrete Time Signal Fourier Series Fourier Transform Discrete Time Signal Z Transform Continuous Time Linear Invariant System Transmission of Signal Through Continuous Time LTI Systems Discrete Time Linear Time Invariant Systems Sampling Continuous Time Signal Laplace Transform Discrete Fourier Transform and Fast Fourier Transform Transmission of Signal Through Discrete Time Lti Systems Miscellaneous Fourier Transform
Communications
Electromagnetics
General Aptitude