Challenging Engineering Problems with Detailed Answers

5. Explain all the performance measures in flat fading. [10 PTS]
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Design a voltage regulator that outputs a stable 3.6 V capable of driving a load of 200 ohms. The main supply is unstable and varies between 4.5V and 5.5V. Your design should highlight the following: (i) Current through the load (ii) The resistance of the resistor in series with the Zener (iii) The connected load (iv) Power ratings for Zener diode and the series resistor
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Design a single-stage common emitter amplifier with a voltage gain 40 dB that operates from a DC supply voltage of +12 V. Use a 2 N2222 transistor, voltage-divider bias, and 330 swamping resistor. The maximum input signal is 25mVrms.
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Draw the circuit for an inverting summing amplifier. (5 points). Solve for the output voltage. Label the circuit properly. (5 points). Include intermediate steps or partial credit won't be available.
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Calculate the necessary Cv rating for a butterfly valve, given a pressure drop of 85 kPa, a specific gravity of 1.25 and a maximum flow rate of 24 cubic meters per hour (m3/hr). Assume there is no flashing or choked flow through the valve.
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A photodetector has an effective bandwidth of 15 GHz and a dark current of 8 nA. For a an incident optical signal that produces 10 A of current what is the associated shot noise root mean square value?
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7) A load that consumes 100 kW and 100 kVAR has: a. A leading P.F. of 45 b. A leading P.F. of 0.707 d. A lagging P.F. of 45 e. A lagging P.F. of 0.707 8) Inductance and capacitance of a transmission line depend upon a. Volume of the line b. Physical configuration d. Frequency e. Current in the line c. Unity power factor f. Zero power factor c. Voltage of the line f. All of the mentioned
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Points Answer the following: a) I) What is meant by Skirt Selectivity? II) An ideal tuned amplifier has a Skirt Selectivity of b) In the PLL, if the frequency of the input and the frequency of the VCO are too far apart, the state is known as c) What is the use of Schmitt trigger in the VCO?
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Shanks' babystep-giantstep algorithm. Let p=1231. Then g=3 is a primitive root mod p. Let n=36. Let h=642. Let s=3^(-n) mod p. Let list 1 be L1=[1, 3, 342, ..., 3^n] (reduced mod p) Let list 2 be L2=[h, h's, h's-2....., h's^nl (reduced mod p). Find a number on both list 1 and list 2.
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A three phase fully controlled rectifier is used to drive a separately excited D.C. motor, and the motor has an armature resistance of 0.2. The motor draws the rated current of 30 A at 900rev/min. The converter is fed by 208 VAC line, and the firing angle of the converter is 60 at rated load. If the motor current is continuous and ripple free, evaluate i. the back emf of the motor at rated load; (3 marks) ii. the voltage constant in V/rpm; (2 marks) iii. the firing angle of the converter at 75% rated speed; and (4 marks) iv. the firing angle of the converter at regenerative braking at rated speed.
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12. In the system of Figure P6.3, let G(s) = K(s + 1) s(s-2)(s+3) Find the range of K for closed-loop stability.
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80tu(t) For a unity feedback system with feedforward transfer function as G(s) = 60(s+34)(s+4)(s+8) s(s+6)(s+17) The type of system is: Find the steady-state error if the input is 80u(t): Find the steady-state error if the input is 80tu(t): Find the steady-state error if the input is 80tu(t):
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What are the benefits and drawbacks of using energy storage batteries in a stand-alone solar photovoltaic system?
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P. 2. Consider a 3-phase induction motor with per-phase equivalent circuit parameters of Ri 0.2 N, R2 = 0.14 N, X = X2 0.7 S2, X m = 12 12. The machine ratings are 400 V, 60 Hz, 6-poles, 1152 rpm, Y-connected. Calculate the following values. (a) slip 1200-1192 0.04 -100= 11% 1200 (b) starting torque (c) maximum torque (d) minimum speed (e) starting current (f) rated current (g) rated power factor (h) power factor at start
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1.Design a sequence detector circuit that produces an output pulse z=1 wheneversequence 1111 appears. Overlapping sequences are accepted; for example, if the input is010101111110 the output is 000000001110. Realize the logic using JK flip-flop, Verify theresult using multisim and use four channel oscilloscope to show the waveforms as result.The waveform should include the CLK, IP signal, and the states of the flip-flop.2 .Design an Odometer that counts from 0 to 99. Verify the circuit using Multisim. You can useany component of your choice from the MUltisim library.Here is a list of components for the hint, it is a suggestion, one can design a circuit of ones own.The students are required to show the screenshot of three results that shows the result at anthe interval of 33 countsComponentQuantityCNTR_4ADEC2D-flip-flop12 input AND gates2Not GateDecd_Hex display12
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A load voltage with flicker can be represented by the following equation: (4.5 Marks) Vload = 170(1+2cos(0.2t))cos(377t). (b) Voltage fluctuation, and (c) Frequency of the fluctuation
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b. In a balanced three-phase system. the source and the load are Y-connected. The phase impedance of the lood is 3- ja and the line connecting the source to the load has an impedance of 0.15 + 0.2 0. In the line voltage (V.) in the load side is 40020 V, find the phase voliage of the source VAN
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a. Power from a Small Source. Suppose 150 gpm of water is taken from a creek and delivered through 1000 ft of 3-in.-diameter polyethylene pipe to a turbine 100 ft lower than the source. Use the rule-of-thumb to estimate the power delivered by the turbine/generator. In a 30-day month, how much electric energy would be generated? I. Find the friction loss 3 mark II. Find the net head available 3 mark III. Find the electrical power delivered
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a) A micro-hydro system has a 3 m head. Calculate the power produced in kW if the waterflow rate is 0.15 m3/s, assuming 85% efficiency.b) Calculate the water volume (m3) of a reservoir that can store 15 kWh. Calculate for waterhead of 1, 2, 3,..10 m. Assume 100% efficiency.c) The water reservoir in (b) has a cubical shape, calculate the wall dimension (L, W, H) foreach calculated water head (1,2,3,..10 m).
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For a unity feedback system with feedforward transfer function as G(s)= s 2(s+6)(s+17)60(s+34)(s+4)(s+8)The type of system is: Find the steady-state error if the input is 80u(t): Find the steady-state error if the input is 80tu(t): Find the steady-state error if the input is 80t 2u(t):
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1. You are an Associate Professional working in the Faculty of Engineering and a newly appointed technician in the Mechanical Workshop asks you to help him with a task he was given. The department recently purchased a new 3-phase lathe, and he is required to wire the power supply. The nameplate of the motor on the lathe indicated that it is delta connected with an equivalent impedance of (5+j15) 2 per phase. The workshop has a balanced star connected supply and you measured the voltage in phase A to be 230 D0 V. (a) Discuss three (3) advantage of using a three phase supply as opposed to a single phase supply (6 marks) (b) Draw a diagram showing a star-connected source supplying a delta-connected load. Show clearly labelled phase voltages, line voltages, phase currents and line currents. (6 marks) (c) If this balanced, star-connected source is connected to the delta-connected load, calculate: i) The phase voltages of the load (4 marks) ii) The phase currents in the load (4 marks) iii) The line currents (3 marks) iv) The total apparent power supplied
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80tu(t) For a unity feedback system with feedforward transfer function as 60(s+34) (s+4) (s+8) G(s): s (s+6) (s+17) The type of system is: Find the steady-state error if the input is 80u(t): Find the steady-state error if the input is 80tu(t): Find the steady-state error if the input is 80tu(t): =
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4. The standard single-phase 12 kVA, 600/120 V, 60 Hz transformer has Rp = 0.08 12 and R2 = 0.04 12. We wish to reconnect it as an autotransformer in a different way to obtain a step down 600/480 V autotransformer. a. Calculate the maximum load the transformer can carry. (15 points) b. Calculate its efficiency at full load with unity power factor.4. The standard single-phase 12 kVA, 600/120 V, 60 Hz transformer has Rp = 0.08 12 and R2 = 0.04 12. We wish to reconnect it as an autotransformer in a different way to obtain a step down 600/480 V autotransformer. a. Calculate the maximum load the transformer can carry. (15 points) b. Calculate its efficiency at full load with unity power factor.
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: Kadj. 2. (20p) A 15-hp, 220-V series DC motor has an armature resistance of 0.1202 and a series field resistance of 0.07 2. At full load, the input current is 60 A, and the rated speed is 1100 rpm. The core losses are 430 W, and mechanical losses are 465 W at full load. Suppose the mechanical losses vary as the speed of the motor, by the fractional power of 2.5, i.e., (speed)2.5. What is the efficiency of the motor at full load? 3. (20m) A 139 1-3 50.30
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