ScientistEngineer SC Electronics Past Paper PDF

## ScientistEngineer SC Electronics **Question 1** The electrostatic potential v = v(r) between two charged concentric sphere of radii r₁ and r₂ kept at potential v₁=2V volts and v₂=0 volts, respectively is given by the solution of : $r^2\frac{\partial^2v}{\partial r^2} + 2r\frac{\partial v}{\part...

## ScientistEngineer SC Electronics **Question 1** The electrostatic potential v = v(r) between two charged concentric sphere of radii r₁ and r₂ kept at potential v₁=2V volts and v₂=0 volts, respectively is given by the solution of : $r^2\frac{\partial^2v}{\partial r^2} + 2r\frac{\partial v}{\partial r} = 0$ The radius of the spherical surface where the electrostatic potential reduces to V volts is | | | |---|---| | (A) $\frac{2r_1r_2}{r_1+r_2}$ | (B) $r_1+r_2$ | | (C) $\frac{r_1^2 + 2r_1r_2}{r_1+r_2}$ | (D) $\frac{r_2^2}{r_1+r_2}$ | **Question 2** The general solution of the differential equation $\frac{d^2y}{dx^2} + y = xe^x$ in terms of arbitrary constant C₁ and C2 is | | | |---|---| | (A) C₁ cos x + C₂ sin x + 0.5ex(x + 1) | (B) C₁ cos x + C₂ sin x + ex | | (C) C₁ cos x + c₂sinx + 0.5ex(x - 1) | (D) C₁ cos x + c₂ sinx + 0.5ex | **Question 3** The determinant and trace of a matrix $A = \begin{bmatrix} 1 & 2 & 3 & 8 \\ 3 & 6a & 7b & 21 \\ 0 & 3a & -6b & 0 \\ 0 & 0 & 4b & 0 \end{bmatrix}$ is -612 and 97, respectively. The value of a + b is | | | |---|---| | (A) 17 | (B) 18 | | (C) 36 | (D) 34 | **Question 4** Consider the following system of linear equations: $\begin{bmatrix} 1 & 2 & 3 \\ 5 & 0 & 10 \\ 11 & 2 & 6\alpha \end{bmatrix} \begin{bmatrix} x_1 \\ x_2 \\ x_3 \end{bmatrix} = \begin{bmatrix} 4 \\ 7 \\ 18 \end{bmatrix}$ The value of α for which the system has infinite solution is | | | |---|---| | (A) 4 | (B) 10 | | (C) 6 | (D) 12 | **Question 5** Which one of the following statement is not true for a real symmetric square matrix M. | | | |---|---| | (A) Eigenvalues of M are always positive. | (B) Eigenvalues of M are always real. | | (C) Eigenvalues of M and MT are always same. | (D) Eigenvectors of distinct eigenvalues of M are orthogonal. | **Question 6** The value of a line integral of a vector function F(r) = zî + xĵ + y k over a helix C:r(t), as shown in the figure, having a radius a and pitch length 2πα is | | | |---|---| | (A) απ | (B) (2α² + 1)π | | (C) 4a² | (D) 3α²π | The image shows a helix going vertically through the center of a cylinder along the z axis. The cylinder axis is aligned with the z axis. The helix goes up and down a certain distance. **Question 7** The values of (a, b, c) so that $\lim_{x \to 0} \frac{ae^x +b cosx-cex}{x sin x} = 2$ is | | | |---|---| | (A) (1, -2, -1) | (B) (2, 1, -1) | | (C) (-1, 1, 2) | (D) (1, -2, 1) | **Question 8** VXA, where A = √(x² + y² + z² - 2xyz), is | | | |---|---| | (A) x + y + z | (B) 0 | | (C) xyz | (D) x+y+z - xyz | **Question 9** The analytic function of a complex variable z = x + iy, whose real part is given by $e^{-x}(x sin y - y cos y)$ is expressed in terms of z and a general constant c by | | | |---|---| | (A) c+ ie⁻ᶻ | (B) c-e⁻ᶻ | | (C) c + ieᶻ | (D) c-2ie⁻²ᶻ | **Question 10** Suppose a length of a rod L = (50 + x) cm, where x is a random variable with probability density f(x) = 1.5(x² - x) if-1 ≤ x ≤ 1 and 0 otherwise. For the bar to have a length between 50 - a cm to 50 + a cm, the value of a (in cm) rounded to second place of decimal is | | | |---|---| | (A) 0.92 | (B) 0.98 | | (C) 0.99 | (D) 0.95 | **Question 11** Let X be the number of trains passing per hour through a railway station. Assuming X has a Poisson's distribution with mean 5. The probability of observing 2 trains or fewer during any given hour is | | | |---|---| | (A) 19e⁻⁵ | (B) 37e⁻⁵ | | (C) 18.5e⁻⁵ | (D) 9.5e⁻⁵ | **Question 12** Consider the circuit shown in the Figure. The switch is open for a long time and is thrown to position 1 at t = 0 s. It is then thrown to position 2 at 5 s. The current, i fort > 5 s is The image displays a circuit with a switch, two voltage sources, a resistor, and an inductor. The switch connects to two different parts of the circuit. One of the sources is a 40V source and the other is a 20V source. The resistor has a value of 3.5 ohms. The inductor has a value of 20 Henries. Each of the two switch positions is connected to a different node of the circuit. Switch position 1 is on the node that is connected to (1) the positive terminal of the 40V source, (2) the positive terminal of the 20V source, and (3) one terminal of the resistor. Switch position 2 is on the node that is connected to both (1) the negative terminal of the 20V source and (2) the other terminal of the resistor. | | | |---|---| | (A) -20+(30-10e⁻⁰·⁰⁵(t⁻⁵)) A | (B) -20(1-e⁻⁰·⁰¹(t⁻⁵)) A | | (C) -20(1-e⁻⁰·⁰¹t) A | (D) -20+ (30-20) e⁻⁰·⁰¹(t⁻⁵) A | **Question 13** The steady state voltage vc across the capacitor, as shown in the figure, is The image shows a circuit containing (1) a 10V AC voltage source, (2) a 10 mH inductor, (3) a 100 mH inductor, (4) a 1 ohm resistor, and a 100 mF capacitor with voltage vc, and (5) a 20A AC current source. All components are connected in series. | | | |---|---| | (A) $\frac{6}{\sqrt{2}}$ cos 20t V | (B) -4√2 cos 20t V | | (C) -4√2 sin 20t V | (D) $\frac{6}{\sqrt{2}}$ sin 20t V | **Question 14** Consider the following magnetically coupled circuit. The value of mutual inductance (in H), if 80% of the total flux generated from one coil links to the other coil, is The image shows a magnetically coupled series circuit containing (1) a 10V AC voltage source, (2) a 10 ohms resistor, (3) a 2 Henries inductor, (4) a 8 Henries inductor, (5) a 1 Farad capacitor connected in parallel with the 8H inductor, and (6) a 10 ohms resistor. The voltage source is connected in series with the 10 ohms resistors and the 2 Henries inductor on the left side of the circuit. The two inductors are connected in series with the 8H-farad parallel combination and the 10 ohm resistor on the right of the circuit. | | | |---|---| | (A) 0.8 | (B) 1.6 | | (C) 3.2 | (D) 6.4 | **Question 15** For the two port network, as shown in the figure, the admittance parameter (Y) matrix (in S) is The image displays a circuit with 2 voltage sources, 2 1 ohm resistors, 2 2 ohm resistors, and a 0.5 Siemens (S) conductance. The whole circuit is symmetrical, with two voltage sources on the left and right side respectively, each having a 1 ohm resistor connected to the positive terminal of the source and a 2 ohm resistor connected to the negative terminal of the source. The two sources are connected by a 1 ohm resistor in the middle of the circuit. A 0.5S conductance is also connected to the 2 ohm resistors on the left and right sides of the circuit. | | | |---|---| | (A) $\begin{bmatrix} 0.4 & 0 \\ -0.2 & 0.5 \end{bmatrix}$ | (B) $\begin{bmatrix} 0.2 & 0 \\ -0.4 & 0.5 \end{bmatrix}$ | | (C) $\begin{bmatrix} 0.4 & -0.2 \\ 0 & 0.5 \end{bmatrix}$ | (D) $\begin{bmatrix} 0.5 & 0.2 \\ 0 & 0.4 \end{bmatrix}$ | **Question 16** In the following graph, the number of possible trees is The image displays a graph with six nodes and seven connected edges. Two nodes are connected to a third central node and each of these two nodes has one edge directed to the central node. Each of the three outer nodes has one edge directed to the central node. The central node has two nodes directed to the two outer nodes, which are connected by one undirected edge. | | | |---|---| | (A) 16 | (B) 8 | | (C) 32 | (D) 4 | **Question 17** The driving point admittance, Y₁₁ of the bridged T-network, as shown in the figure, is The image displays a circuit containing (1) an AC voltage source connected in series with a 1 ohm resistor and a 1 Farad capacitor, (2) a 1 Farad capacitor connected in series, and (3) another 1 ohm resistor. | | | |---|---| | (A) $\frac{2s^2+5s+2}{s^2+s+1}$ | (B) $\frac{2s^2+5s+1}{s^2+5s+1}$ | | (C) $\frac{s^2+5s+2}{2s^2+5s+1}$ | (D) $\frac{2s^2+5s-1}{s^2+5s+2}$ | **Question 18** The frequency response for a linear time invariant system is given by h(f) = $\frac{2}{1+j2πf}$ The step repsonse of the system is | | | |---|---| | (A) (1-e⁻ᵗ)u(t) | (B) 2(1-e⁻²ᵗ)u(t) | | (C) 2(1-e⁻ᵗ)u(t) | (D) 2(1-e⁻ᵗ/²)u(t) | **Question 19** The characteristic equation of a given system is: $s³ + 4s² + Ks + 12 = 0$ The range of K in order to ensure the system is stable is | | | |---|---| | (A) K > 12 | (B) K > 3 | | (C) 4 <K < 12 | (D) K < 12 | **Question 20** Consider a closed loop system whose open loop transfer function is given by: G(s)H(s) = $\frac{K}{(T₁ς + 1) (T₂5 + 1)}$ For the system to be stable, which of the following condition is TRUE: | | | |---|---| | (A) All positive values of K, τ₁ and T₂. | (B) Positive value of K and negative values of t₁ and t₂. | | (C) Negative value of K and positive values of t₁ and T₂. | (D) All negative values of K, τ₁ and T₂. | **Question 21** The forward path transfer function of a system with integral control H(s) = K/s is G(s) = $\frac{1}{\sqrt{3}S + 1}$ The value of K, when the closed loop resonance peak is 2/√3 is | | | |---|---| | (A) 4√3 | (B) 2√3 | | (C) 2/√3 | (D) 2/√3 | **Question 22** A control system with PD controller is shown in the figure The image shows a control system with a PD controller. The input is X(s), the output is Y(s), and there is a 1/(1 + s²) block. The PD controller is a block with a transfer function Kp + KDs. If the ramp error constant is 100, the value of Kp is | | | |---|---| | (A) 5 | (B) 20 | | (C) 10 | (D) 40 | **Question 23** If $A = \begin{bmatrix} 10 & 0 \\ 0 & 10 \end{bmatrix}$, the state transition matrix $e^{At}$ is | | | |---|---| | (A) $\begin{bmatrix} e^{10t} & 0 \\ 0 & e^{10t} \end{bmatrix}$ | (B) $\begin{bmatrix} e^{-10t} & 0 \\ 0 & e^{-10t} \end{bmatrix}$ | | (C) $\begin{bmatrix} 0 & e^{0.1t} \\ 0 & e^{0.1t} \end{bmatrix}$ | (D) $\begin{bmatrix} 0 & e^{-0.1t} \\ 0 & e^{-0.1t} \end{bmatrix}$ | **Question 24** A silicon bar is doped with phosphorus with donor concentration, ND=10¹⁶ cm⁻³. If the intrinsic carrier concentration of silicon at T=300 K is n₁=1.5x10¹⁰ cm⁻³ and assuming complete impurity ionization, the equilibrium electron concentration, n₀ and hole concentration, p₀ are | | | |---|---| | (A) n₀=10¹⁶ cm⁻³ and p₀=5.5x10⁴ cm⁻³ | (B) n₀=10¹⁶ cm⁻³ and p₀=2.25x10⁴ cm⁻³ | | (C) n₀=10⁴ cm⁻³ and p₀=2.25x10⁴ cm⁻³| (D) n₀=2.25x10⁴ cm⁻³ and p₀=10¹⁶ cm⁻³ | **Question 25** Consider an abrupt p-n junction diode with built in potential of 0.7 V. If its junction capacitance, Cj is 4 pF at a reverse bias of VR=1.3 V, then the value of Cj when VR=7.3 V is | | | |---|---| | (A) 4 pF | (B) 2 pF | | (C) 1 pF | (D) 8 pF | **Question 26** Consider an enhancement type N-channel MOSFET with µn=650 cm²/V-s, Cox=6.9x10⁻⁸ F/cm², VTH = 0.65 V and L=1.25 µm. The channel width, W of the MOSFET, if it is operating in saturation with VGS=5V and ID=4 mA, is | | | |---|---| | (A) 11.8 µm | (B) 23.6 µm | | (C) 5.9 µm | (D) 51.33 µm | **Question 27** Consider the following circuit with R₁ = R₁ = 10 Ω. vs is a 20 V square wave of period 10 msec and the diode is ideal. The average value of load voltage, VL is The image displays a voltage divider with R1 and R2 acting as the resistors. The top of the voltage divider is connected to an AC voltage source with voltage VS. The bottom of the voltage divider is connected to a diode. The other side of the diode is attached to a load resistor, Rl. | | | |---|---| | (A) 5 V | (B) 10 V | | (C) 2.5 V | (D) 20 V | **Question 28** If in the circuit shown below, VBE = 0.75 V then VCE is The image displays a transistor circuit. An AC voltage source with 6V is connected in series with a 1 mA current source. The positive node of the current source is connected to the base of a transistor. The emitter of the transistor is connected to ground. The collector of the transistor is connected to a 2 kOhm resistor and a 100 Ohm resistor. The other ends of the resistors are connected to a 10V source. | | | |---|---| | (A) 3.85 V | (B) 7.7 V | | (C) 1.42 V | (D) 2.85 V | **Question 29** The n-channel JFET circuit, as shown in the figure, is self-biased. If Rp= 3 kΩ, RD = 1 kΩ, VDD = 14 V, Vps at quiescent point is 6 V and assuming negligible gate leakage current, the VGs at quiescent point is The image shows a JFET circuit with a single transistor. The source of the transistor is connected to a resistor Rs, which is in parallel with a resistor RG. The drain of the transistor is connected to resistor RD and then to a 14 Volt source, VDD. | | | |---|---| | (A) -8 V | (B) -1 V | | (C) -2 V | (D) -4 V | **Question 30** Consider the following circuit with transistor parameter, VBE = 0.726 V, β = 99. If VT = 26mV, the corner frequency, f₁ of the amplifier is The image displays a transistor circuit. On the left side of the circuit, a voltage source with voltage Vi is connected in series with a 40 kOhm resistor, a 1 uF capacitor, and another 40 kOhm resistor, going to the base of a transistor. The collector of the transistor is connected to a 1 kOhm resistor and a 774 Ohm resistor, then to the positive terminal of a 3.4 Volt DC voltage source. The negative terminal of the source is connected to the emitter of the transistor. | | | |---|---| | (A) 15.7/π Hz | (B) 31.4/π Hz | | (C) 31.25/π Hz | (D) 62.5/π Hz | **Question 31** Consider the following ideal op-amp circuit with R₁ = 10 kn, and R2 = 20 ΚΩ. The voltage gain, $\frac{Vo}{V2-V1}$ is The image displays a circuit with two op-amps. Each op-amp has two inputs and one output. The first op-amp is connected to voltage sources V1 and V2. One voltage source, V1, is connected to the positive terminal of the first op-amp, and the other voltage source, V2, is connected to the positive terminal of the second op-amp. The negative terminals of both op-amps are connected in parallel to the outputs of the other op-amps. Each op-amp has two resistors, R1 and R2, connected to the negative terminal. The values of R1 and R2 are 10 kOhms and 20 kOhms, respectively. The output of both op-amps is connected to one another, and the output of the circuit is the output of the second op-amp, Vo. | | | |---|---| | (A) 1 | (B) 2 | | (C) 4 | (D) 8 | **Question 32** For class A amplifier, the ratio of: (efficiency of transformer coupled amplifier) / (efficiency of transformer less amplifier) is | | | |---|---| | (A) 1 | (B) 2 | | (C) 0.5 | (D) 3 | **Question 33** A CMOS implementation of a logic gate is shown in the following figure with A and B as inputs and Y as output. The Boolean logic function realized by the circuit is The image shows a CMOS logic gate with an output labelled Y. There are four horizontal lines, with labels VDD, A+, B+, and B-. VDD is connected to the leftmost node of the circuit. A+ is connected to a node on the upper half of the circuit. B+ is connected to a node on the lower half of the circuit, and both B+ and B- are connected to a single node. Both these nodes are connected to a node on the rightmost output, Y. | | | |---|---| | (A) AND | (B) NAND | | (C) NOR | (D) OR | **Question 34** The Boolean function, Vo implemented from the CMOS logic, as shown in the figure, is The image shows a CMOS logic gate with an output labelled Vo. There are four horizontal lines, with labels VDD, A-, B-, and B+. VDD is connected to the leftmost node of the circuit. On the upper half of the circuit, A- is connected to a node which is connected to a node labelled E-. E- is connected to the leftmost node of B-. B- is connected to the leftmost node of the output, Vo. B+ is connected to a node which is connected to a node labelled C. C is connected to the leftmost node of A-, which is also connected to D. D is connected to a node to the right of E. C is connected to a node to the right of E with another node labelled E+ connected to it. | | | |---|---| | (A) Vo = A(D + E) + BC | (B) Vo = A(D + E) + BC | | (C) Vo = (A + DE)(B + C) | (D) Vo = (A + DE)(B + C) | **Question 35** The dynamic range and SNR of an ideal 12-bit ADC is | | | |---|---| | (A) 72.24 dB and 74 dB, respectively | (B) 74 dB and 72.24 dB, respectively | | (C) 72 dB and 70 dB, respectively | (D) 70 dB and 72 dB, respectively | **Question 36** A 4 kb memory is designed as a square with number of rows equal to number of columns. The minimum address line needed for column decoder is | | | |---|---| | (A) 6 | (B) 7 | | (C) 8 | (D) 10 | **Question 37** A 4k x 8bit RAM is interfaced to an 8-bit microprocessor. If the address of the first memory location in the RAM is 4000 H, the address of the last memory location will be | | | |---|---| | (A) OFFF H | (B) 47FF H | | (C) 4FFF H | (D) 8000 H | **Question 38** A radio link from the moon to the earth has a moon-based 5λ long right-handed monofilar axial-mode helical antenna and a 2 W transmitter operating at 1.5 GHz. Considering the earth-moon distance as 1.27 light-seconds, the effective aperture for the earth-based antenna, in order to deliver 10⁻¹⁴ W to the receiver, is | | | |---|---| | (A) 1.27π m² | (B) 48.39π m² | | (C) 4.03π m² | (D) 5.38π m² | **Question 39** 4 identical isotropic point sources are arranged in square array as shown in the figure. The spacing, d, between each source and the centre point of the array is 3λ/8. Sources 1 and 2 are in-phase, and sources 3 and 4 in opposite phase with respect to 1 and 2. The expression for normalized electric field pattern, En(Ø)is The image displays four point sources arranged in a square. The space between two adjacent point sources is labelled d. The point sources are labelled 1, 2, 3, and 4. Point sources 1 and 2 are on the left and right side of the square, respectively. Point sources 3 and 4 are on the top and bottom of the square, respectively. The center of the square is labeled with a dot. | | | |---|---| | (A) En(Ø) = cos(ẞd cos Ø) – sin(ẞd sin Ø) | (B) En(Ø) = sin(ẞd sin Ø) - cos(ẞd sin Ø) | | (C) En(Ø) = sin(ẞd cos Ø) – sin(ẞd sin Ø) | (D) En(Ø) = cos(ẞd cos Ø) - cos(ẞd sin Ø) | **Question 40** A long coaxial cable carries a uniform volume charge density, p on the inner cylinder, having radius a, and a uniform surface charge density on the outer cylindrical shell, having radius b. The coaxial cable, as a whole, is electrically neutral. The electric field, at a radial distance, s, between the cylinders (a< s <b), is | | | |---|---| | (A) 0 | (B) E = $\frac{pS}{2ε₀}$ | | (C) E = $\frac{ρa^2}{2ε₀s}$ | (D) E = $\frac{ρa^2}{2ε₀}$ | **Question 41** Three charges are situated at the three corners of a square, having side a, as shown in the figure. The work done to bring another charge, +q, from far away to the fourth corner of the square is The image displays a square with four nodes. Three nodes are labelled with charge -q, +q, and -q, with -q labels on the top and bottom nodes of the sides of the square, and +q on the left side node. The sides of the square have length a. | | | |---|---| | (A) $\frac{q^2}{4πε₀a} (-2 + \frac{1}{\sqrt{2}})$ | (B) $\frac{q^2}{2πε₀a} (-2 + \frac{1}{\sqrt{2}})$ | | (C) $\frac{q^2}{4πε₀a} (2 - \frac{1}{\sqrt{2}})$ | (D) $\frac{q^2}{πε₀a} (2 - \frac{1}{\sqrt{2}})$ | **Question 42** For a linear, uniform array of 10 isotropic elements with a separation of quarter wavelength (d = λ/4) between the elements, the directivity of the array with end-fire configuration is | | | |---|---| | (A) Same as that of broadside array configuration | (B) Double of broadside array configuration | | (C) Half of broadside array configuration | (D) None of the above | **Question 43** The magnitude of reflection coefficient for impedances having a negative real part is | | | |---|---| | (A) Less than 1 | (B) Equal to 1 | | (C) Greater than 1 | (D) Less than 0 | **Question 44** A short dipole antenna 10 cm in length is driven uniformly along its length with a sinusoidal current of peak value 1 amp. The frequency at which this antenna radiates 1 watt of power is | | | |---|---| | (A) $3\sqrt{\frac{3}{377\pi}}$ GHz | (B) $\sqrt{\frac{3}{377\pi}}$ GHz | | (C) $\frac{3}{\sqrt{377\pi}}$ GHz | (D) $\frac{3\sqrt{3}}{377\pi}$ GHz | **Question 45** A BJT is encapsulated in a plastic housing and mounted on a heat sink having thermal resistance from heat sink to ambient of 3.75°C/W. The total power dissipation is expected to be 20W at an ambient temperature of 20°C. Considering that the maximum junction temperature should not exceed 175°C, the maximum allowed thermal resistance rating for the BJT casing is | | | |---|---| | (A) 7.75°C/W | (B) 4°C/W | | (C) 3.75°C/W | (D) 1°C/W | **Question 46** A low noise amplifier operating at 10GHz with 200MHz bandwidth has a transducer gain of 25dB, noise figure of 2.5dB, output 1dB compression point, Pout, 1dB of 20dBm, and third order intercept point (referenced to output), IPout of 40dBm. The spurious free dynamic range of the amplifier, assuming that the amplifier is operating at 300K and the minimum detectable signal is defined as 1dB above the noise floor is approximately | | | |---|---| | (A) 68dB | (B) 63dB | | (C) 80dB | (D) 60dB | **Question 47** A lossless T-junction power divider has a source impedance of 50Ω. The output characteristic impedances of the power divider, so that the output powers are in a 2:1 ratio will be | | | |---|---| | (A) 150Ω and 75Ω | (B) 100Ω and 50Ω | | (C) 150Ω and 50Ω | (D) None of the above | **Question 48** Consider a sinusoidal signal x(n) with arbitrary frequency ω & amplitude A. The value of peak magnitude (Mpeak) of spectrum of N-point FFT of x(n) will be | | | |---|---| | (A) Mpeak = A. N | (B) Mpeak = A. N/π | | (C) A. N/2π ≤ Mpeak ≤ A. N/π | (D) A. N/π ≤ Mpeak ≤ A. N/2 | **Question 49** Bandpass sampling of a signal of bandwidth B i. Reduces sampling speed requirement of ADC ii. If fs ≥ 2B there will be no aliasing iii. It increases memory requirement iv. If fs ≥ 2B there may be aliasing | | | |---|---| | (A) i & ii are true | (B) i & iv are true | | (C) Only i is true | (D) i & iii are true | **Question 50** A communication channel is having 3 kHz bandwidth & available SNR of 15. The channel capacity, when available SNR is reduced to 7 and channel bandwidth is increased to 4KHz, will | | | |---|---| | (A) remains same | (B) decrease by 1 kbps | | (C) increase by 1 kbps | (D) decrease by 17 kbps | **Question 51** Puncturing in forward error correcting codes results i. Higher coding gain or better error correcting capability ii. Higher code rates iii. Increased distance between codes iv. No impact on coding performance | | | |---|---| | (A) Only iv is true | (B) Only ii is true | | (C) Only iii is true | (D) i & ii are false | **Question 52** The symbol rate of a communication system operating on 2000 Kbps information rate, employing 8-PSK modulation and FEC coding with code rate 5/6 is | | | |---|---| | (A) 6000Ksps | (B) 5000Ksps | | (C) 800Ksps | (D) 666Ksps | **Question 53** GaAs LED युक्त प्रकाशिक तंतु की युग्मन दक्षता 0.08 है। प्रकाशिक हानि होगी. | | | |---|---| | (A) 8dB | (B) 11dB | | (C) 29dB | (D) 20dB | **Question 54** For a communication system i. Source coding is used to save bandwidth ii. Channel coding adds redundant information systematically iii. Channel coding improves communication quality iv. Channel coding saves bandwidth | | | |---|---| | (A) All are