GATE 1994 Electronics & Communication
50 questions across 1 session
For a dipole antenna
If a pure resistance load, when connected to a lossless 75-ohm line, produces a VSWR of 3 on the line, then the load impedance can only be 25 ohms.
In order to reduce the harmonic distortion in an amplifier, its dynamic range has to be _________
A PLA can be used
A dynamic RAM consists of
Indicate whether the following statement is TRUE/FALSE: Give reason for your answer. If G(s) is a stable transfer function, then $$F\left( s \right) = {1 \over {G\left( s \right)}}...
A series LCR circuit consisting of $$R = 10\Omega $$, $$\left| {{X_L}} \right|\,\,\, = 20\Omega $$ and $$\left| {{X_C}} \right|\,\,\, = 20\Omega $$, is connected across an a.c. sup...
A generator of internal impedance, Z G , delivers maximum power to a load impedance, Z L , only if Z L = ................
A ring oscillator consisting of 5 inverters is running at a frequency of 1.0 MH$$_z$$. The progagation delay per gate is ______
A ramp voltage, v(t) = 100 t Volts, is applied to an RC differentiating circuit with R = $$5k\Omega$$ and C = $$4\mu F$$.The maximum output voltage is
Tachometer feedback in a d.c. position control system enhances stability.
The condition, that a 2-port network is reciprocal, can be expressed in terms of its ABCD parameters as ...............
The poles of a continuous time oscillator are ___________.
If the open loop transfer function is a ratio of a numerator polynomial of degree 'm' and a denominator polynomial of degree 'n', then the integer (n-m) represents the number of
The Fourier Series of an odd periodic function, contains only
A common emitter transistor amplifier has a collector current of 1.0 mA when its base current is 25 $$\mu$$A at the room temperature. It's input resistance is approximately equal t...
The response of an LCR circuit to a step input is (a) Over damped (b) Critically damped (c) Oscillatory If the transfer function has (1) poles on the negative real axis (2) poles o...
Match the following with List-1 with List-2 List-1 (a) Very low response at very high frequencies. (b) Overshoot (c) Synchro-control transformer output List-2 (1) Low pass systems...
If G(s) is a stable transfer function, then $$F\left(s\right)=\frac1{G\left(s\right)}$$ is always a stable transfer function.
The open loop frequency response of a system at two particular frequencies are given by: 1.2 $$\angle - 180^\circ $$ and 1.0 $$\angle - 190^\circ $$. The closed loop unity feedback...
A class-A transformer coupled, transistor power Amplifier is required to deliver a power rating of the transistor should not be less than.
A Boolean function, F , given as sum of product (SOP) terms as F= $$\sum {} $$m(3,4,5,6) with A,B, and C as inputs. The function, F, can be expreeed on the Karnaugh's map shown bel...
$$y = {e^{ - 2x}}$$ is a solution of the differential equation $$\,{y^{11}} + {y^1} - 2y = 0$$
The function $$y = {x^2} + {{250} \over x}$$ at $$x=5$$ attains
Match the List-1 (type of 8-bit ADC) with List-2(Minimum conversion time in clock cycles) List - 1 A. Successive approximation B. Dual-slope C. Parallel Comparator List - 2 1) 1 2)...
$$v\left(t\right)\;=5\left[\cos\left(10^6\mathrm{πt}\right)\;-\;\sin\left(10^3\mathrm{πt}\right)\times\sin\left(10^6\mathrm{πt}\right)\right]$$ represents
A rectangular hollow metal waveguide of internal cross-section of $$7.366\,\,cm\,\, \times \,\,3.556\,cm$$ carries a 3 GHz signal in the $$T{E_{10}}$$-mode. Calculate the maximum p...
The bandwidth required for the transmission of a PCM signal increases by a factor of ________ when the number of quantization levels is increased from 4 to 64.
The interior of a $${{20} \over 3}\,\,cm\,\, \times \,\,{{20} \over 4}\,\,cm$$ rectangular waveguide is completely filled with a dielectric of $${ \in _r} = 4$$. Waves of free spac...
A plane electromagnetic wave traveling along the +z-direction, has its electric field given by E x = 2 cos $$\left( {\omega t} \right)$$ and E y = 2 cos $$\left( {\omega t + {{90}^...
A load impedance (200 + j0) $$\Omega $$ is to be matched to a 50$$\Omega $$ lossless transmission line by using a quarter wave line transformer (QWT). The characteristic impedance...
A wave traveling in the $$+Z$$-direction, is the resultant of two linearly polarized components, $${E_x}\,\,\, = \,\,\,\,\,\,3$$ $$\,\,\,\,\cos \omega t$$ and $$\,{E_y}\,\,\,\, = \...
Match the following. GROUP-1 (A) Hartley (B) Wein-bridge (C) Crystal GROUP-2 (1) Low frequency oscillator (2) High frequency oscillator (3) Stable frequency oscillator (4) Relaxati...
The frequency compensation is used in OP-Amps to increase its___________
The following system of equations $${{x_1} + {x_2} + {x_3} = 3}$$ $${{x_1} - {x_3} = 0}$$ $${{x_1} - {x_2} + {x_3} = 1}$$ has
The transit time of a current carriers through the channel of an FET decides its ____________characteristics.
In the output stage of a standard TTL, we have a diode between the emitter of the pull up transistor and the collector of the pull-down transistor. The purpose of this diode is to...
The 3-dB bandwidth of a typical second- order system with the transfer function $${{C\left( s \right)} \over {R(s)}} = {{\omega _n^2} \over {{s^2} + 2\xi {\omega _n}s + \omega _n^2...
The rank of $$\left( {m \times n} \right)$$ matrix $$\left( {m < n} \right)$$ cannot be more then
Match each of the items $$A, B, C$$ with an appropriate item from $$1, 2, 3, 4$$ and $$5$$ List-$${\rm I}$$ $$(P)$$ $${a_1}{{{d^2}y} \over {d{x^2}}} + {a_2}y{{dy} \over {dx}} + {a_...
Synchronous counters are _____ than the ripple counters.
A small concentration of minority carries is injected into a homogeneous semiconductor crystal at one point. An electric field of 10 V/cm is applied across the crystal and this mov...
A p-type silicon sample has a higher conductivity compared to an n-type sample having the same dopant concentration.
The transit time of the current carriers through the channel of an FET decides its ____________characteristics.
Channel current is reduced on application of a more positive voltage to the gate of a depletion mode n-channel MOSFET.
The threshold voltage of an n-channel MOSFET can be increased by
Match each of the items A, B and C with an appropriate item from 1, 2, 3, 4 and 5. List - 1 (A) $${a_1}{{{d^{2y}}} \over {d{x^2}}} + {a_2}y{{dy} \over {dx}} + {a_3}y = {a_4}$$ (B)...
The laplace transform of a unit ramp function starting at t=a, is
A signal, f(t) = $${e^{ - at}}$$ u(t), where u(t) is the unit step function, is applied to the input of a low-pass filter having $$\left| {H(\omega )} \right| = {b \over {\sqrt {{\...
Two spacecrafts are separated by 3000 km. Each has a paraboloidal reflector antenna of 0.85 m diameter operating at a frequency of 2 GHz with an aperture efficiency of 64%. If the...