Explore BrainMass

Electrical Engineering

Complex impedance and phase angle

Refer to diagram in attached file. 1. Derive an expression for the complex impedance between terminals A&B referring to the reactances as Xc & XL. Express the answer in the form of (real part + j * imaginary part) 2. Calculate the phase angle of the current I relative to the voltage Vin for a source frequency of 3kHz(must

Wireless Networks Question

Please help with the following problem. Mobile IP was intended to work with legacy correspondent hosts and legacy applications. However, some advantages may be gained if correspondent hosts are aware of mobility in certain ways. a) If a correspondent host is able to do IP-in-IP decapsulation, it may be able to communicate

Calculating the Maximum Calling Rate

You have a bandwidth of 10 MHz (per direction) in a single-cell system and want to deploy a wireless telephone system. You have the following options: analog 30-kHz channels (as in AMPS), digital 30-kHz channels (each supporting 3 users as in IS-54), digital 200-kHz channels (each supporting 8 users as in GSM), or CDMA with 10-k

Wireless Networks Questions

You want to download a 5 Mbit file over a 10-Mbps Rayleigh fading channel in the 1800 MHz frequency band. You are traveling at 6 km/h and use 1000-bit packets. The fading margin of the channel is 20 dB. If any packet is received in error during the transfer, the operation is aborted. (a) What is the probability that you successf

PI Controller and Nyquist Analysis

(Complete problem with equations found in attachment). Problem 1 A very common industrial controller is the proportional and integral (PI) controller. It has a transfer function, , kp is the proportional gain, Ti is the "reset time" For an integrating process, P(s) = 2/s, investigate the positive root locus for

Speedup and Efficiency

Question: Given 100 processors for a computation with 5% of the code that cannot be paralleled, compute the speedup and efficiency.

Saturated NPN Transistor

A saturated npn transistor has a base to emitter applied voltage of 0.6V. The collector to emitter voltage is 0.2V. The collector current is 12mA. The beta value of the transistor is 30. What is the emitter current?

Important Information About RC Series Circuit

An RC series circuit has a voltage source of 10Vac, a resistor of 10ohms, and a capacitor with an impedance of -j10ohms. How do I find the magnitude and phase angle of the current flow through the capacitor?

Solving for Digital Signal Processing

Question: Consider the signal: x(n)={1,0,-1,2,3} Fourier transform X(w)=Xreal(w)+j(Xi(w)). Determine and represent the signal y(w) that gives the fourier transform of Y(w)=Xi(w)+Xreal(w)e^exp(j2w).

Interpreting a Step Signal

Please see the attachment. The image is described by y(t)=t-tu(t-1)-t(u(t-2))+t(u(t-3)). I don't get this. Please point out where the signal turns on and off and why. To me, it looks like a ramp, a step, and then a ramp with neg amplitude. I can do the rest of the problem, i.e. the laplace transform and the other parts

Design a series controller

The process of a unity-feedback control system has the transfer function 100 Gp(s) = ------------------------ s^2 + 10 s + 100 Design a series controller (a PD, PI or PID) so that the following performance specifications are satisfied. Steady-state error due to a step i

Autocorrelation and Tao

I have a question from my ECE 302 class regarding the mean of a random process given a particular autocorrelation function in terms of tao. I know Variance=(mean-square)-(mean)^2 and I know that the (mean-square)=autocorrelation function with tao set to 0, but I don't know how to get the mean if I don't know the variance of

Transfer Function Analysis for a Unity Feedback System

For a unity feedback system with open-loop transfer function, G(s) = K(s+alpha)/(s^2 + 4s + 1): a) Find all values of alpha such that the system is stable for K = 2. b) If the unity feedback closes around this G(s) and an input is a unit step r(t) = 1u(t), what is the stead-state error, e_ss, as a function of alpha and K? c)

Thevenin Equivalent Voltage

A resistor, R, was connected to a circuit box as shown. The voltage, v, was measured. The resistor was changed, and the voltage was measured again. The results are shown in the table. Determine the Thevenin equivalent voltage vt of the circuit within the box. Determine the Thevenin equivalent resistance Rt of the circuit?

Solving Input Impedance

See attachment for the diagram. Question: Determine how the input impedance Z (jw) = Vi (jw) / Ii (jw) behaves at extremely high or low frequencies.

Solving: Fourier Series

Compute the Fourier series coefficient of the periodic function shown in the figure(view attachment) and defined as: X(t) = A 0 <= t <= T/3 0 T/3 <= t < T

8 x 8 JPEG Image

Consider the following 8x8 8-bits image: 26 25 30 30 37 37 37 37 7 28 29 30 37 37 37 37 6 9 31 28 37 37 37 37 4 5 10 30 37 37 37 37 9 9 9

Phasor Current

Hi, I need some assistance for the following question: Question: For the following circuit, find the phasor current. Please see attachment for circuit diagram.

System Modelling (Output: Density)

Two tanks are arranged as shown in the attachment. Salt and water are added into the first tank at rates {see attachment}. The tanks are well mixed and the salt dissolves completely. The flow between the two tanks depends on the pressure difference {see attachment}. The flow out of te second tank is given by {see attachment}. Bo

System Modelling - Output and State Differential Equation

Consider the ice-cream manufacture process shown in the attachment. The ice-cream is made up of the following ingredients: i) Liquid (cream, milk, water etc.) added at a rate r1 [kg/hr] and with a density p1 [kg/1]. ... {see attachment for more details} (a) Find a model for the process with height in the tank and density

Determining the Voltage for Capacitor

Please see the attached file for diagram. Question: Determine Vc(t) for t>0. The voltage across the capacitor in figure just before the switch is changed is given below: Vc(0) = -7V Io = 12mA C = 0.55muF R1 = 7kOhms R2 = 3.3 kOhms

Simulink - Modelling - Linear Systems

1. A system with input u(t) has the following model ... (see attachment) Find the linearized state space model about the steady state with ... (see attachment) 2. Draw the simulink implementation diagram required to simulate the non-linear system and its linearized version from question 1. The input signal will come from the

Numerical Integration and the Runge Kutta Method

a) For a fixed delta t(i+1)= delta t, the linear equation, x = Ax, x(t0)=x0 has the solution... Show that the Runge Kutta method (below) is 3rd order and not 4th order for the above linear equation. bi) Find the exact solution of x = -2x, x0 = 3 bii) Find the numerical solution for two simulation steps using explicit Euler a

Solving for Thevenin Equivalent Resistance

Question: Find the Thevenin equivalent resistance seen by resistor R3 in the circuit. Compute the Thevenin (open-circuit) voltage and the Norton (short-circuit) current when R3 is the load. VS1=VS2= 450V. Please see diagram in the attached file.

Superposition of current

Using superposition, determine the component of the current through R3 that is due to VS2. VS1 = VS2 = 450V. (see diagram in attached file)