AP PGECET- 2016(Electronics & Communication)

The function f(x, y) = x² + y² + x + 12 has minimum value at the point

A random variable X has probability density function f(x) = kxe^–λx, x ≥0 then k =

If the coefficient of correlation is 0.98, then the variables are

The order of the differential equation (dy/dx)² + 5y^1/3 = x is

An integrating factor of xý + y = x³y⁶

Which one of the following is a series method?

The impulse response of an LTI system is given by h[n] = 2δ[n – 20]. Determine the output y[n] if the input is x[n] = n²

The input output relationship of a system is given by y[n] = cos[x(n)]. The system is

The Fourier series coefficients of a periodic signal x(t) with time period T are X_k. Find the signal y(t) whose Fourier series coefficients are given by Y_k = 2X_k and time period is T/5.

The signals x₁(t) and x₂(t) are both band-limited to (-ω₁, +ω₁) and (-ω₂, +ω₂) respectively. The Nyquist sampling rate for the signal x₁(t)x₂(t) will be

The response of an LTI discrete-time system to a periodic input with period N is

The step response of an LTI system whose impulse response h(n) = u(n) is

If the Fourier series coefficients of a signal are periodic, then the signal must be

Lex X_k represent the discrete-time Fourier series (DTFS) coefficients of the periodic sequence x(n) with period N. The DTFS co-efficients of the signal (-1)ⁿx(n) in terms of X_k are

The Fourier transform of the exponential signal e^jωot is

Frequency response of a system with h(n) = δ(n) – δ(n – 1) is given by

The ROC of a causal finite-duration discrete-time signal is

Linear phase systems have a constant

In an N-point DFT of a finite duration signal x(n) of length L, the value of N should be

The algorithm used to compute any set of equally spaced samples of Fourier transform on the unit circle is

Total number of complex multiplications required in radix -2 DIT-FFT algorithm is

The steady-state error of a feedback control system with an acceleration input becomes finite in a

If for a control system, the Laplace transform of error e(t) is given as 8(s+3)/ s(s+10) the steady state value of the error works out as

The equation 2s⁴ + s³ + 3s² + 5s + 10 = 0 has _______ roots in the left half od s-plane

Given a unity feedback control system with G(s) = K/ s(s+4), the value of K for a damping ratio of 0.5 is

The input to a controller is

If the Nyquist plot of the loop transfer function G(s)H(s) of a closed-loop system encloses the (-1, j0) point in the G(s)H(s) plane, the gain margin of the system is

A system with gain margin close to unity or a phase margin close to zero is

Peak overshoot of step-input response of an underdamped second-order system is explicitly indicative of

A phase lag-lead network shifts the phase of a control signal in order that the phase of the output

The Bode plot of the transfer function G(s) = s is

24 voice channels (4 KHz bandwidth) are sampled at 8 times the Nyquist rate and multiplexed. Each voice channel is delta modulated. 1 bit is added per frame for transmitting control information. What is the data rate of transmission?

Lex X be a continuous random variable with uniform PDF defined by f_x(x) = 1/2π, for 0 < x < 2π and zero elsewhere. Find σ_x.

The stationary process has

In a modulator, it is found that the amplitude spectrum of the signal at the output of the modulator consists of a component f_c, the carrier frequency and one component each at f_c + f_m and f_c – f_m where f_m is the modulating signal frequency. The modulator used is

If a Gaussian process X(t) is applied to the stable linear filter, then the random process developed at the output of the filter will be

Which of the following is incorrect ?

The SSB-SC is used for the following application :

What does a logic 1 Delta Modulation (DM) bit indicate ?

The asymptotic value of E_b/N_o required to achieve the data rate equal to the channel capacity when the channel bandwidth tends to infinity is equal to

The golden rule for encoding messages with unequal probabilities is to

The output Signal to Noise Ratio, (SNR)_o of matched filter depends only on

In _______ multiple access is achieved by allocating different time slots for the different users.

Cellular CDMA system uses what modulation method ?

The only one signal waveform that produces zero inter symbol interference (ISI) is

The length of antenna depends on

For a broad side linear array which of the following is not correct?

The phase velocity of waves propagating in a hollow metal waveguide is

If the diameter of a λ/2 dipole antenna is increased from λ/100 to λ/50 then its

The directive gain cannot be stated as

An electromagnetic wave has electric field component along Y – direction and magnetic field component along X – direction. The electromagnetic wave is propagating along

The lower cut-off frequency of a rectangular wave guide with inside dimensions (3 × 4.5 cm) operating at 10 GHz is

During night which layer does not exist?

The dominant mode of rectangular waveguide is

Vector potential is a vector

A uniform plane wave in air is incident normally on an infinitely thick slab. If the refractive index of the glass slab is 1.5, then the percentage of the incident power that is reflected from the air-glass interface is

In an impedance Smith chart, a clockwise movement along a constant resistance circle gives rise to

A composite voltage V = 10 sin100t + 10 cos100t is applied across a series combination of a capacitor of 1μf and resistance of 20 KΩ. The average power dissipation in the resistance is

The driving point impedance function Z(s) = (s² + 2s + 2)/ (s² + s + 1) can be realized

A 100Ω, 1W resistor and 800Ω, 2W resistor are connected in series. The maximum DC voltage that can be applied continuously to the series circuit without exceeding the power limit of any of the resistors is

Under steady state condition

In the series RLC circuit, the power factor of the circuit at f = f_L  (Lower Frequency) and f = f₀ (resonance frequency)

In parallel RLC circuit, if L=8H and C=2F then the value of critical resistance is

The transient free condition in RL and RC circuits with AC excitation will not depend on

A Unit impulse voltage is applied to one port network, which has two linear components. If the current through the network is 0 for t<0 and decays exponentially for t>0 then the network consists of

A graph of network has 4 nodes and 7 branches. The number of links(l), with respect to the chosen tree, would be

Choose the logic gate family which is having minimum propagation delay

An 8085 microprocessor based system uses a 4K × 8 bit RAM with a starting address of AA00 H. The address of the last byte in this RAM is

How many memory IC’s of capacity 2K × 4 are required to construct a memory capacity of 15K × 8?

The present output Q_n of an edge triggered JK flip-flop is logic 1. If k=1 then Q_n+1

A 12-bit (3-digit) DAC that uses the BCD input code has a full scale output of 9.99 V. The value of V_out for an input of 0110 1001 0101 is

The starting address of below program is 0100 H

LXI SP, 00FF H
LXI H, 0701 H
MVI M, 20 H
MVI A, 20 H
SUB M

The content of accumulator when the program counter reaches 010B H is

A 1 micro-second pulse can be converted into a 1 milli-second pulse by using

What is the maximum frequency with which a 4-bit binary ripple counter can work, if the propagation delay from CLK to Q of each flip-flop is 24 ns?

The Boolean function f(w,x,y,z) = Ʃm(5,7,9,11,13,15) is independent of variables

The initial sequence of 4-bit Johnson counter is 1110, what will be the sequence after third clock pulse

The logic function (A+B)(A’ +B’) can be implemented by giving the inputs A and B to a two input

The function f(A,B,C,D) = Ʃm(0,1,4,6,7,8,10,14,15), the number of prime implicants and essential prime implicants are

A 4.6 V is given as input to the counter type ADC and SAR type ADC then the digital output produced respectively

The current gain of a BJT drops at high frequencies because of

Which of the following fabrication is suitable for maintaining the PN junction area to the required accuracy?

Moore’s law relates to

The value of transport factor in a BJT is effected by

Two 10 V identical zener diodes are connected back to back, the maximum voltage drop across the diodes when they are conducting is

A PN junction exhibits a transition capacitive effect of several ______ farads in reverse bias, but may have many _____ farads of diffusion capacitance in the forward biased state

An amplifier has R_i = 2 KΩ and R0 = 40 KΩ and A_v = 90. The amplifier is modified to provide 10% negative voltage feedback in series with input. The values of R_if and R_of respectively are(in ohms)

Class-A power amplifier delivers 10W to a load with input signal power of 200mW. The power gain is

Transistor has h_fe = 50, its h_fc =

A cascade amplifier has higher cut off frequency

An ideal current controlled voltage source has

In BJT, Sensitivity of β (common emitter current gain) with respect to α (common base current gain) is

A differential amplifier has a differential gain of 20000 and CMRR = 80dB. Common mode gain is

Which of the following h-parameters relations is incorrect ?

Which of the following is true for n type semiconductor ?

If 10 V is the peak voltage across the secondary of the transformer in a half wave rectifier with capacitive filter, peak inverse voltage of the diode will be

When an electron moves through a potential difference of 10 V, the energy acquired by it will be

Which of the following represents the Cascade configuration?

The scaling factor of an MOS device is α using constant voltage scaling model, the gate area of the device will be scaled by