GATE 2001 Question Paper With Solutions

SECTION - A
1. This question consists of TWENTY-FIVE sub-questions (1.1 – 1.25) of ONE mark
each. For each of these sub-questions, four possible alternatives (A,B, C and D)
are given, out of which ONLY ONE is correct. Indicate the correct answer by
darkening the appropriate bubble against the question number on the left hand
side of the Objective Response Sheet (ORS). You may use the answer book
provided for any rough work, if needed.

1.5. The region of convergence of the z-transform of a unit step function is
(a) z > 1 (b) z < 1
(c) (Real part of z) > 0 (d) (Real part of z) < 0

1.7. MOSFET can be used as a
(a) current controlled capacitor (b) voltage controlled capacitor
(c) current controlled inductor (d) voltage controlled inductor

1.8. The effective channel length of a MOSFET in saturation decreases with increase in
(a) gate voltage (b) drain voltage
(c) source voltage (d) body voltage

1.10. The 2’s complement representation of –17 is
(a) 01110 (b) 01111 (c) 11110 (d) 10001

1.11. Consider the following two statements:
Statement 1: A stable multi-vibrator can be used for generating square wave.
Statement 2: B stable multi-vibrator can be used for storing binary information.
(a) Only statement 1 is correct
(b) Only statement 2 is correct
(c) Both the statements 1 and 2 are correct
(d) Both the statements 1 and 2 are incorrect

1.13. An 8085 microprocessor based system uses a 4K × 8-bit RAM whose starting
address is AA00. The address of the last byte in this RAM is
(a) 0FFFH (b) 1000 H (c) B9FF H (d) BA00 H

15. If the characteristic equation of a closed-loop system is
s2+2S+2= 0 , then the system is
(a) over damped (b) critically damped
(c) underdamped (d) undamped

1.19. A band limited signal is sampled at the Nyquist rate. The signal can be recovered
by passing the samples through
(a) an RC filter (b) an envelope detector
(c) a PLL
(d) an ideal low-pass filter with appropriate bandwidth

1.21. If a signal f(t) has energy E, the energy of the signal f(2t) is equal to
(a) E (b)E/2 (c) 2E (d) 4E

1.22. A transmission line is distortion-less if
(a)RL=1/GC (b) RL = GC (c) LG = RC (d) RG = LC

1.24. The phase velocity of waves propagating in a hollow metal waveguide is
(a) greater than the velocity of light in free space.
(b) less than the velocity of light in free space.
(c) equal to the velocity of light in free space.
(d) equal to the group velocity.

1.25. The dominant mode in a rectangular waveguide is TE10, because this mode has
(a) no attenuation (b) no cut-off
(c) no magnetic field component (d) the highest cut-off wavelength

2. This question consists of TWENTY-FIVE sub-questions (2.1 – 2.25) of TWO marks
each. For each of these sub-questions, four possible alternatives (A, B, C and D)
are given, out of which ONLY ONE is correct. Indicate the correct answer by
darkening the appropriate bubble against the question number on the left hand
side of the Objective Response Sheet (ORS). You may use the answer book
provided for any rough work, if needed.

2.18 A video transmission system transmits 625 picture frames per second. Each
frame consists of a 400 × 400 pixel grid with 64 intensity levels per pixel. The
data rate of the system is
(a) 16 Mbps (b) 100 Mbps (c) 600 Mbps (d) 6.4 Gbps

2.22 A material has conductivity of 10-2 mho/m and a relative permittivity of 4. The
frequency at which the conduction current in the medium is equal to the
displacement current is
(a) 45 MHz (b) 90 MHz (c) 450 MHz (d) 900 MHz

2.23 A uniform plane electromagnetic wave incident normally on a plane surface of a
dielectric material is reflected with a VSWR of 3. What is the percentage of
incident power that is reflected?
(a) 10% (b) 25% (c) 50% (d) 75%

2.24 A medium wave radio transmitter operating at a wavelength of 492 m has a
tower antenna of height 124m. What is the radiation resistance of the antenna?
(a) 25Ω (b) 36.5Ω (c) 50Ω (d) 73Ω

SECTION – B
This section consists of TWENTY questions of FIVE marks each. Attempt ANY FIFTEEN
questions. Answers must be given in the answer book provided.

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