Recent content by Mr.Green

  1. M

    What areas of study does electrical engineering cover

    Not a bit but a lot, especially in Engineering Electromagnetics and in Communication Systems and in Microwave Engineering. I think there are a little chemistry in High Voltage.
  2. M

    Delta Power System

    I don't check whether the numerical values are true or not, but there are errors in calculating the real power in the resistors. On assumption that the currents values are true. PA12 is OK. PB12 = I1 - I2 = (|(49.68A<-68.6 - 49.68A<-128.6)|^2) * 12 = something By "|" I mean the magnitude...
  3. M

    Engineering Finding Rth of an RLC circuit

    It depends on whether you have a DC circuit or an AC circuit. 1) DC A) Since the reactance of an inductor is given by: XL = j*(2 * pi * f * L) and (f = 0) in a DC circuit, so inductor is replaced by a short circuit. ( An element with zero reactance or resistance) B) For the capacitor: Xc = 1...
  4. M

    Need a book suggestion

    For the topics you mentioned I think the following book will be a great help: Thomas L. Floyd, Digital Fundamentals
  5. M

    Engineering Help with Second Order Circuits

    Dear Friend di/dt = A2 * t * (-20 * e (-20t) ) + A2 * e(-20t) The derivative of multiplied terms.
  6. M

    Simple Voltage Problem

    The output voltage is the same voltage that appears across the Diode. If we have some ideas about the voltgae across the diode we will know the output voltage. During the positive cycle the diode is reversed biased and we can replace it with an open circuit...
  7. M

    Finding Vc

    Look at the Hint carefully. It says that you should integrate I(t) over a period of time to find the voltage. If you want to integrate you should have a function, i.e. current as a function of time. So...obtain the relation between the current and the time. Then integrate it over the desired...
  8. M

    Transistor biasing question.

    This has error in number. 3.6 - 640 Ib - 0.7 = 0
  9. M

    Frequency Response/Content/stuff

    GREAT. You are doing well.
  10. M

    Engineering Basic Circuits - Thevenin's Thm explanation

    Q6/ 1) The KVL is written for a closed loop. So, choose a closed loop and go on. For the perimeter the KVL is written as it is seen in the solution. Let's Write KVL for the inner portion to see what problem we will encounter: -35 - 20 * 4 - 3 * 4 + Vcs = 0 where: Vcs is the voltage across...
  11. M

    Phasor Voltage and Voltage RMS value

    Phasor voltage represents the instantaneous value of the voltage. For example in time t the voltage may have a value of 120V and one second later it may have a voltage of 50V. The rms voltage is (let say) the ac voltage that is equivalent to the dc voltage. This is not very clear. Isn't it...
  12. M

    Frequency Response/Content/stuff

    Frequency Response: Is a function (in frequency domain) that shows how element properties (Admittance or Impedance for example), a current, a voltage or many other quantities in a circuit varies with frequency. Transfer Function: Is a function (in frequency domain) that relates between the...
  13. M

    Gain bandwidth product

    Sorry for being intrude, but it is worth while to know that the dB values never should be multiplied or divided. The only allowable operation on dB quantities are addition and subtraction. Also since the GBWP units is Hz, so the Gain should be unitless (Volt/Volt).
  14. M

    Engineering ELEG - DC Motor Control Systems Problem

    Yes, it is wrong. I attach the right SFG. Use it to obtain the transfer function and then substitue Hi/He with the given expression. I think it will work. Ω is the capital form of omega which represents the speed in radian/second. Ωm(s) is the Laplace transfor of ωm(t). This represents the...
  15. M

    Voltage & Resistors

    OK. But afterward you should do it yourself so that you deeply understand it. Remember that you can't make muscles looking me lift weights :) . I1 = V/(R1 + R2) = 0.076 mAmp I2 = V/(R3 + R4) = 0.096 mAmp V2 = I1 * R2 = 1.368 V V4 = I2 * R4 = 2.016 V Vx = V2 - V4 = - 0.645 (It is negative...