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 cm

^{2}, µ_{n}= 800 cm^{2}/(V-s) in the base region and depletion layer widths are negligible, then the collector current I_{c}(in mA) at room temperature is __________. (Given: thermal voltage V_{T}= 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 V

_{BE}= 700 mV. The thermal voltage (V_{T}) 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 A

_{1}= 0.2 μm × 0.2 μm and A_{2}= 300 μm × 300 μm. Assuming that all other device parameters are identical, kT/q = 26 mV, the intrinsic carrier concentration is 1 × 10^{10}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., V_{BE1}– V_{BE2}) 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 (t

_{ch}) of 10 μm is available for conduction. The built-in voltage of the gate P^{+}N junction (V_{bi}) is -1 V. When the gate to source voltage (V_{GS}) 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 V_{GS}= -3 V isQuestions Asked from BJT and FET (Marks 2)

Number in Brackets after Paper Indicates No. of Questions

GATE ECE Subjects

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

Network Theory

Control Systems

Digital Circuits

General Aptitude

Electronic Devices and VLSI

Analog Circuits

Engineering Mathematics

Microprocessors

Communications

Electromagnetics