GATE 1991 Electronics & Communication
24 questions across 1 session
In the radiation pattern of a 3-element array of isotropic radiators equally spaced at distances of $${\lambda /4}$$ it is required to place a null at an angle of 33.56 degrees off...
In a series RLC high Q circuit, the current peaks at a frequency
Two two-port networks are connected in cascade. The combination is to be represented as a single two-port network. The parameters of the network are obtained by multiplying the ind...
The necessary and sufficient condition for a rational function of s, T(s) to be driving point impedance of an RC network is that all poles and zeros should be
A second order system has a transfer function given by $$\mathrm G\left(\mathrm s\right)\;=\;\frac{25}{\mathrm s^2\;+\;8\mathrm s\;+\;25}$$ .If the system, initially at rest is sub...
A unity feedback control system has the open loop transfer function $$G\left(s\right)\;=\;\frac{4\left(1\;+\;2s\right)}{s^2\left(s\;+\;2\right)}$$ .If the input to the system is a...
The characteristic equation of a feedback control system is given by s 3 +5s 2 +(K + 6)s + K =0 Where K > 0 is a scalar variable parameter. In the root loci diagram of the system t...
The open-loop transfer function of a feedback control system is G(s)=$${1 \over {{{\left( {s + 1} \right)}^3}}}$$ The gain margin of the system is
Two non-inverting amplifiers, one having a unity gain and other having a gain of twenty, are made using identical operational gain amplifier, the amplifier with gain twenty has
A uniform plane electromagnetic wave traveling in free-space enters into a lossless medium at normal incidence. In the medium its velocity reduces by 50% and in free space sets up...
The program given below is run on an 8085 based microcomputer system. Determine the contents of the registers: PC, SP, B, C, H, L after a half instruction is executed. LOC 2000 STA...
Two resistors $$\,{R_1}$$ and $$\,{R_2}$$ (in ohms) at temperatures $${T_1}{}^ \circ K$$ and $${T_2}{}^ \circ K$$ respectively, are connected in series. Their equivalent noise temp...
The input impedance of a short-circuited lossless transmission line guarter wave long is
A SR FLIP-FLOP can be converted into a T FLIP-FLOP by connecting ___ to Q and ___ to $$\overline Q $$.
The electric field component of a uniform plane electromagnetic wave propagating in the $$Y$$-direction in a lossless medium will satisfy the equation
In a board side array of 20 isotropic radiators, equally spaced at a distance of $$\lambda /2$$, the veam width between first nulls is
A binary source has symbol probabilities 0.8 and 0.2. If extension coding (blocks of 4 symbols) is used, the lower and upper bounds on the average code word length are : (a)lower__...
A linear second order single input continuous-time system is described by the following set of differential equations $$$\eqalign{ & \mathop {{x_1}}\limits^ \bullet \left( t \right...
The four variable function f is given in terms of min-terms as: f (A B C D ) = $$\sum {} $$m (2,3,8,10,11,12,14,15 .) Using the K-map minimize the function in the sum of products f...
A silicon sample is uniformly doped with 10 16 phosphorous atoms/cm 3 and 2 ×10 16 boron atoms/cm 3 . If all the dopants are fully ionized, the material is
The small signal capacitances of an abrupt P + −N junction is 1 nF at zero bias. If the built-in voltage is 1 volt, the capacitance at a reverse bias voltage of 99 volts is equal t...
A signal has frequency components from 300 Hz to 1.8 KHz. The minimum possible rate at which the signal has to be sampled is ______ (fill in the blank).
An excitation is applied to a system at $$t = T$$ and its response is zero for $$ - \infty < t < T$$. Such a system is a
The voltage across an impedance in a network is V(s) = Z(s) I(s), where V(s), Z(s) and $${\rm I}$$(s) are the Laplace Transforms of the corresponding time functions V(t), z(t) and...