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Choose the correct alternative from the following (10 x 2) 1. A band-pass filter will (a) pass frequencies each side of a band (b) attenuate low frequencies but not high frequencies (c) attenuate frequencies on each side of a band (d) attenuate high frequencies but not low frequencies 2. If each pulse of the sequence to be detected is in ⸺ shape, the pulse can be detected without ISI (a) Sine (b) Cosine (c) Sinc (d) None of the mentioned 3. A pulse shaping filter should satisfy two requirements. They are (a) Should be realizable (b) Should have proper roil off factor (c) Both of the mentioned (d) None of the mentioned 4. If a noiseless channel band-limited to 5 kHz sampled every 1 mSec, what wilt be the value of sampling frequency? (a) 250 samples/sec (b) 500 samples/sec (c) 800 samples/sec (d) 1000 samples/sec 5. In the channel coding theorem, channel capacity decides the ⸺  permissible rate at which error-free transmission is possible. (a) Maximum (b) Minimum (c) Constant (d...

Choose the correct alternative for the following: 10 x 2 1. The autocorrelation function R(τ) of the signal X(t) = Vsinωt is given by (a) 0.5V 2 cosωt (b) V 2 cosωt (c) V 2 cos 2 ωt (d) 2V 2 cos 2 ωt 2. Which of the following cannot be the Fourier series expansion of a periodic signal? (a) x(t) = 2cos6t + 3cos3t (b) x(t) = 2cosπt + 7 cost (c) x(t) = cost + 0.5 (d) x(t) = 2 cos1.5πt + sin3.5πt  3. Consider a white noise of 2-sided spectral density 2 x 10⁻⁶ Hz applied to a simple RC low pass filter whose 3 dB cut-off frequency is 4 kHz. The mean squared value of the noise output will be (a) 4π x 10⁻³ V² (b) 2π x 10⁻³ V² (c) 4π x 10⁻³ V² (d) π x 10⁻³ V² 4. Find the magnetic field intensity due to an infinite sheet of current 5 A and charge density of 12j units in the positive y-direction and the 2 component is below the sheet. (a) -6 (b) 12k (c) 6 (d) 60 5. In a VSB system the power contained in the sidebands due...

Choose the correct answer for the following (10 x 2) 1. For a linear electromagnetic circuit, which statement is true? (a) Field energy is equal to the co-energy (b) Field energy is greater than co-energy (c) Field energy is less than co-energy (d) Co-energy is zero 2. If  E̅ i s the electric field intensity, V(V x E̅) is equal to (a)   E̅ (b) |E̅| (c) Null vector (d) Zero 3. For the scalar field   the magnitude of the gradient at the point (1, 3) is (a)  (b)  (c) (d) 9/2 4. A regression model is used to express K as a function of another variable X. This implies (a) There is a causal relationship between Y and X (d) A value of X may be used to estimate a value of F (c) The values of X exactly determine values of Y (d) There is no causal relationship between F and X 5. The Fourier transform o f  f(t) = e -a|t|  wh ere a > 0 is (a)   (b)   (c)  (d) None of the above 6. An example of a noise that is not natural...

Answer the following questions (10 x 2) What will be the value of ∇(∇xE), if the E electric field intensity? The divergence of the curl of any vector field is zero. Write the examples of noises that are not naturally occurring. Noise in a communication system is basically undesirable or unwanted signals that get randomly added to the actual information-carrying signal. Resultantly, causes disturbances in the original signal being transmitted from one end to another. So, on the basis of source noise in the communication channel are of two types: Natural noise gets generated due to either natural phenomena or atmospheric actions like solar flares, radiation in space, electronic storms etc. Internal Noise is the fundamental noise that gets generated by the electronic equipment involved in the system itself. They are called so because these are nothing but an integral part of the system. Thermal Noise   Thermal noise occurs due to the vibration of charge carriers within an electri...

Answer all of the following questions (10 x 2) What is Digital Modulation? Digital modulation is the process of encoding a digital information signal into the amplitude, phase, or frequency of the transmitted signal. In general, a modulation technique encodes several bits into one symbol, and the rate of symbol transmission determines the bandwidth of the transmitted signal. Since the signal bandwidth is determined by the symbol rate, having a large number of bits per symbol generally yields a higher data rate for a given signal bandwidth. However, the larger the number of bits per symbol, the greater the required received SNR for a given target BER. Explain Diode Envelope detection in brief. The AM diode detector is an envelope detector – it provides an output of the envelope of the signal. As such the diode detector or demodulator is able to provide an output proportional to the amplitude of the envelope of the amplitude modulated signal. The signal diode detector consists of two mai...

Choose the correct option (10 x 2) 1. The laplace equation has (a) Two solutions (b) Infinite solutions (c) No solutions (d) One solution 2. A material has conductivity of 10⁻² mho/in and a relative permittivity of 4. The frequency at which conduction current is equal to displacement current is (a) 45 MHz (b) 90 MHz (c) 450 MHz (d) 900 MHz 3. The magnetic field in an ideal conductor is (a) Zero (b) Infinite (c) Finite (d) Same as outside field 4. Statement 1 - Inside a conductor electric field is always zero. Statement 2 - A conductor is always an equipotential surface. (a) True, True (b) False, False (c) False, True (d) True, False 5. An integration of any vector around a closed path is always equal to the Curl of surface integral of that vector, this statement is known as : (a) Ampere law (b) Stoke's theorem (c) Biot Savart law (d) Curl 6. The probability density function of the envelope of narrowband Gaussian noise is (a) Poisson (b) Gaussian (c) Rayleigh (d) Rician 7. Quantizat...