GATE ECE 1989 | GATE ECE Paper Questions with Solutions

GATE ECE 1989

GATE ECE

The feedback amplifier shown in Fig.has:

GATE ECE 1989 Analog Circuits - Feedback Amplifier Question 3 English

Of the four biasing circuits shown in Fig. For a BJT, indicate the one which can have maximum bias stability:

A signal of bandwidth 3.5 kHz has peak-to-peak and rms amplitudes of 4 V and 0.2 V, respectively. This signal is passed through a linear PCM coder and then transmitted over a channel capable of supporting a transmission rate of 60 kbps. Calculate the maximum signal-to-quantization-noise ratio that can be obtained using this system.

A part of a communication system consists of an amplifier of effective noise temperature, $$Te = \,\,21\,\,{}^ \circ K\,$$, and a gain of 13 dB, followed by a cable with a loss of 3 dB. Assuming the ambient temperature to be $$300{}^ \circ \,K$$, we have for this part of the communication system,

Zero mean Gaussian noise of variance N is applied to a half wave rectifier. The mean squared value of the rectifier output will be:

A source produces 4 symbols with probabilities $${1 \over 2},\,{1 \over 4},\,{1 \over 8}\,\,and\,\,{1 \over 8}.$$ For this source, a practical coding scheme has an average codeword lenght of 2 bits/symbols. The efficiency of the code is :

For the input signal, x(t), shown in Fig.

(a) Sketch the impulse response, h(t), of the matched filter.
(b) Sketch the output, y(t), of the matched filter. Fully label your diagram.
(c) If the input to the matched filter consists of the signal, x(t), plus additive white noise of two sided spectral density of $${10^{ - 6}}$$ watts/Hz, find the maximum output SNR of the matched filter.

GATE ECE 1989 Communications - Digital Communication Systems Question 7 English

In binary data transmission DPSK is preferred to PSK because

Nyquist plot consider a feed back system where the OLTF is: $$G(s) = {1 \over {s\left( {2s + 1} \right)\left( {s + 1} \right)}}.$$ Determine the asymptote which the nyquist plot approaches as $$\omega \to 0.$$ Find also the range of 'k' in terms of the cross over frequency $${\omega _{PC}}$$ for stability.

From the Nicholas chart, one can determine the following quantities pertaining to a closed loop system:

In order to stabilize the system shown in fig. T_i should satisfy:

GATE ECE 1989 Control Systems - Stability Question 17 English

A chemical reactor has three sensors indicating the following conditions:-
(1) Pressure (P) is low or high'
(2) Temperature (T) is low or high' and
(3) Liquid level (L) is low or high.

its has two controls - Heater (H) which is either on or off and inlet value (V) which is open or close. The controls are operated as per Table.

(a) Using the convertion High =1, Low = 0, On=1, Off=0, Open=1 and Closed=0, draw the Karnaugh maps for H and V.

(b) Obtain the minimal product of sums expressions for H and V.

A logic family has threshold voltage $${V_T}$$= 2V, minimum guaranteed output high voltage $${V_{OH}}$$= 4V, minimum accepted input high voltage $${V_{IH}}$$ = 3V, maximum guaranteed output low voltage $${V_{OL}}$$ = 1V, and maximum accepted input low voltage N $${V_{IL}}$$ =1.5V. Its noise margin is

Among the digital IC-families-ECL, TTL and CMOS:

Indicate which of the following logic gates can be used to realize all possible combinational Logic functions:

Design a rectangilar hollow metal waveguide to operate in the X-band such that at an operating free-space wavelength of 3.2 cm
(a) The guide-wavelength for the $$T{E_{{{10}^ - }}}$$ mode is 40% more than the operating free-space wavelength.
(b) The cut-off wavelength for the $$T{M_{{{11}^ - }}}$$ mode is 40% of the cut-off wavelength for the $$T{E_{{{10}^ - }}}$$ mode.

In the case of ground wave propagation, at far-off distances from the transmitting tower antenna, the Poynting vector is

Two vertically oriented half wave dipoles are spaced 1.5 wavelengths apart to from an array. Calculate the half power beam widths of the major lobes of the array, in the horizontal plane for the following two cases when the dipoles are fed with

(a) equal and in - phase currents (Broadside array)
(b) equal currents but with a phase difference of 540⁰ between the two currents (End fire array)

The electric field strength at a far-off point P due to a point charge + q, located at the origin O is 100 millivolts/metre. The point charge is now enclosed by a perfectly conducting hollow metal sphere with its centre at the origin O. The electric field strength at the point, P,

A 50 ohm lossless transmission line has a pure reactance of (j100) ohms as its load. The VSWR in the line is :

The skin - depth of copper at a frequency of $$3 GHz$$ is $$1$$ micron ($${{{10}^{ - 6}}}$$ metre). At $$12 GHz$$, for a non - magnetic conductor whose conductivity is $$1/9$$ times that of copper, the skin $$-$$ depth would be

In a microprocessor system, the stack is used for

The half - power bandwidth of the resonant circuit of figure can be increased by

GATE ECE 1989 Network Theory - Sinusoidal Steady State Response Question 8 English

For the transfer function of a physical two-port network

The condition AD - BC = 1 for a two-port network implies that the network is a

In the circuit of figure, the power dissipated in the register R is 1W when only source '1' is present and '2' replaced by a short.The power dissipated in the same registor R is 4W when only source '2' is present and '1' is replaced by a short.When both the source '1' and '2' are present, the power dissipated in R will be:

GATE ECE 1989 Network Theory - Network Theorems Question 33 English

A 10 Ω resistor, a 1 H inductor and 1 $$\mathrm{μF}$$ capacitor are connected in parallel.The combination is driven by a unit step current.Under the steady state condition, the source current flows through

A load, Z_L = R_L + jX_L is to be matched, using an ideal transformer, to a generator of internal impedance, Z_S = R_S + jX_S. The turns ratio of the transformer required is