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Electrical Engineering

Partial fraction expansion

We have a function (see Attachment). Using a partial fraction expansion of Y(s) find Y(z) when T=0.2 seconds.

Magnetically suspended steel ball

A magnetically suspended steel ball can be described by the linear equation as shown in the attachment. The state variables are x1 = position, and x2 = velocity, and both are measurable. Select a feedback format so that the system is critically damped and the settling time (2% criterion) is 2 seconds. Solve for k1 and k2.

Full Wave Center Tap Bridge Rectifier

In the attached image, how is VDC across the load resistor found? The practice test has an answer of 28.24 ignoring the ripple voltage. VDC across the resister is Vout right? So, Vsecondary - the voltage drop in the diode = Vout = VDC So, if the secondary winding has 40voltage - .7V drop in the top resistor, that's 39.3V

Digital signal processing problem

The problem(2-61) is from the third edition of digital signal processing(proakis+manolakis) 2-61 an audio signal s(t)generated by a loud speaker is reflected at two different walls with reflection coefficients r1 and r2. the signal x(t) recorded by amicrophone close to the loud speaker, after sampling is;

Theoretical and analytical questions

1- Sketch the dc transfer characteristic of the circuit shown below. [VBE(on) = 0.7 V] and also explain the theory behind the working of this circuit. (see diagram in attached file) 2- what is the relationship between gain and bandwidth in amplifiers with negative feedback? How about positive feedback? - what is the adv

Common emitter amplifer

The parameters of the transistor are Beta=100 and Va=100V. Find the DC voltages at the base and emittter terminals. See attachment for circuit.

Transistor design problem

Redesign the circuit showin using Vcc=9V such that the voltage drop across Rc = 1/3VCC and the voltage drop across Re=1/3VCC. Assume Bf=100. the quiescent collector current is to be IcQ=.4mA and the current through R1 and R2 should be approximately .2Icq. Replace each transistor with the closest standard value. What is the v

Bias Stable Transisor Design Problem

Please help with the following problem. The DC load line and Q point of the circuit are shown next to the circuit. For the transistor, Beta=120. Find Re, R1, and R2 such that the circuit is bias stable. Is it valid for me to do a KVL around the C-E loop using ic=4.8ma and vce=6v (ie=ic (b+1/b)) to find RE? And then get

Rearrange formula (charging battery)

A battery is charged. The relationship between the charging current, i amperes and the time, t hours passed, is given by the formula: i = 3 e to the power of -0.36 t Show the formula for i can be rearranged to give the time t as t= 1 divided by 0.36 log e (3/i) Show all steps of working this out please!

Average current and average voltage

A full-wave bridge rectifier circuit with a 1-kohms load operates from a 120-V (rms) 60-Hz household supply through a 10-to-1 step-down transformer having a single secondary winding. It uses four diodes, each of which can be modeled to have a 0.7-V drop for any current. What is the fraction of a cycle that each diode conducts? W

Signal Processing

See attachment for better symbol representation. 1. Find and sketch the spectrum of the following signal. x(t) = cos(t) + cos (2t)*cos(3t) (Express the trigonometric functions in terms of complex exponentials using one of Euler's formulae, then perform the arithmetic (multiplication) and then express x(t) in terms of sep

Primary and Secondary Voltage

A transformer has a primary voltage of 115v and a secondary voltage of 24v. If the number of turns in the primary is 345, how many turns are in the secondary? (a) 8 (b) 72 (c) 690 or (d) 1,653 ?

Finding total resistance of two devices

A circuit contains two devices that are connected in parallel. If the resistances of one of these devices is 12ohms and the resistance of the other device is 4ohms, the total resistance of the two devices is? (a) 0.0625 (b) 0.333 ohms (c) 3 ohms (D) 16 ohms

Finite State Machine

Finite State Machine A finite state machine (FSM) is either deterministic or non-deterministic. A deterministic FSM (DFSM) is a FSM with at most one transition for each symbol and state. A non-deterministic FSM (NDFSM) is a FSM whose transition function maps input symbols and states to a (possibly empty) set of next states. T

'Digital Filtering'- MATCAD problem

Plot the frequency response and the poles and zeroes in each case. Use a sampling frequency of one rad/sec. Compare the filter frequency responses. (See attachment for full question).

Transmission Delay

A two-port bridge connects on the end of a cable of length X m. to the end of a similar cable of length 3x/2 m. Hosts are attached at various points on the cable system, which operates as a shared-access LAN implementing the CSMA/CD protocol with a minimum frame length of 512 bits. The bridge imparts a delay in forwarding frame

IP address routing

Suppose a router has built up the routing table shown in Table below. The router can deliver packets directly over interfaces 0 and 1, or it can forward packets to routers R2, R3, or R4. Describe what the router does with a packet addressed to each of the following destinations (see Attachment)

Calculate the delay angle (alpha)

The three-phase half-wave converter in figure below is operated from a three-phase wye-connected 220V, 60 Hz supply and the load resistance is R=10 ohms. If the average output voltage is 25% of the maximum possible average output voltage, calculate the delay angle (alpha). See Attached File.

Determine the peak-to-peak ripple current

An Rl load as shown in figure below is controlled by a chopper. If load resistance R=0.25 ohms, inductance L=20 mH, supply voltage Vs=600V, battery voltage E=150V, and chopping frequency F=250 Hz, determine the peak-to-peak ripple current (delta I). See Attached File.

RMS current ratings of a diode

The waveforms of the current flowing through a diode are shown in the figure below. Determine the RMS current ratings of the diode.