Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

WolframAlpha guide on electrical engineering

  1. May 21, 2009 #1

    WolframAlpha is a freely available computational engine that can supplement already existing software such as mathematica, maple, mathlab, or excel. The purpose of this mini-guide is to go over some of its functionality with emphasis on electrical engineering.


    Dimensional analysis:

    WolframAlpha recognizes many common units. It will simplify dimensions and scale units. For example,

    Code (Text):
    farad * henry
    will generate [time]^2

    Code (Text):
    0.01 uF to pF
    will generate 10,000 pF or 10 nF

    WolframAlpha also can tap its database to pull up a conversion formula from the context

    Code (Text):
    convert 25 MHz to meters
    will convert the frequency to wavelength 12 meters

    Code (Text):
    find energy in 100 uF at 10 KV
    will give energy in a capacitor,

    or to find inductance to resonate with 10 nF capacitor at 100 Khz; just say that

    Code (Text):
    find inductance for 10 nF at 100 KHz
    output 253 nH

    Also if you haven't memorized resistor color bands already, you can still look them up

    Code (Text):
    resistor yellow purple red
    output: 4.7K

    Complex numbers and phasors:

    Working in polar form is supported in W|A. By typing an impedance in rectangular form

    Code (Text):
    30 + 45i
    we are quickly given its magnitude and phase of 54, and 56 degrees

    and likewise, we can indicate a phasor in polar form with an exponential e

    Code (Text):
    e^(i pi)
    generates -1

    we can also manipulate phasors algebraically

    Code (Text):
    100 e^(i 45 deg) + 25 e^(i 30 deg)
    output: magnitude = 124, phase = 42 deg

    indicate degrees with “deg” otherwise W|A will interpret it in radians.

    Solving equations:

    To solve [itex] x^2 - 2x + 1= 0[/itex], enter the equation as it is

    Code (Text):
    x^2 - 2x + 1 = 0
    output x = 1

    and W|A solves it. Don't even have to specify the variable to be solved.

    Solving systems of equations is just as easy,

    [tex] v_1 + v_2 + v_3 = 4 [/tex]

    [tex] v_1 - v_2 = 10 [/tex]

    [tex] v_1 - 3v_2 + 5v_3 = 8 [/tex]

    simply type

    Code (Text):
    v1 + v2 + v3 = 4, v1-v2 = 10, v1 - 3v2 + 5v3 = 8
    output v1 = 23/3, v2 = -7/3, v3 = -4/3

    just make sure that the equations are separated by a comma.

    Differential equations are supported as well. An nth number of apostrophes indicates an nth derivative, and proceed as before. For example to solve

    [tex] \frac{d^2y}{dx^2} - \frac{dy}{dx} - 2y = 0 \indent y(0) = 1, y'(0) = 2 [/tex]

    enter the code as follows,

    Code (Text):
    y'' – y' - 2 y = 0, y(0) = 1, y'(0) = 2
    and we get a solution y = e^2x as well as a plot that can be saved in pdf format, and printed out.

    We can also maximize and minimize

    Code (Text):
    max 1 - x^2
    finds maximum of 1

    Logic gates and boolean algebra:

    Converts number bases,

    Code (Text):
    binary 1111101 to hex
    = 7d

    We can also work with boolean expression in WolramAlpha, for example

    Code (Text):
    (x or y) and (x or !y)
    generates a truth table:

    http://img200.imageshack.us/img200/9384/truthtable.gif [Broken]

    a schematic with logic gates, and even simplifies the expression to a minimal form

    http://img268.imageshack.us/img268/3233/scehmatic.gif [Broken]

    Here is the supported syntax:
    Code (Text):

    NOT = !
    OR = ||
    AND = &&


    More on calculus:

    W|A can perform basic calculus

    take derivatives:

    [tex] \frac{d}{dt} cos(t) [/tex]

    Code (Text):
    derivative cos(t)
    do integration:

    [tex] \int \frac{1}{x+1} dx [/tex]

    Code (Text):
    integrate 1/(x+1) dx
    and take Laplace and Fourier transforms:

    [tex] \mathcal{L}(x^2), \mathcal{F}(e^x) [/tex]

    Code (Text):
    laplace x^2
    Code (Text):
    fourier  e^x


    If you want to graph a transfer function for instance,

    [tex] H(s) = \frac{s+10}{s^2 + 4s + 8} [/tex]


    Code (Text):
     graph (s + 10)/(s^2 + 4s + 8)
    and here we have

    http://img32.imageshack.us/img32/9715/graph.gif [Broken]


    WolframAlpha uniquely combines different tools into a one freely available package and that expands our tool box. This mini-guide doesn't cover all of W|A, it merely touches upon features that can be used in electrical engineering, for more information visit their examples page


    also, W|A is said to expand in the future, enabling more functionality, and tools.
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. May 21, 2009 #2


    User Avatar

    Staff: Mentor

    Thanks for putting that together, waht. I've stickied this thread to help us learn how to utilize W|A.

    Any further posts in this thread should be about tips on how to use W|A and its features. Discussions about W|A and its implications for eductaion, etc., belong in a different thread, like this one: https://www.physicsforums.com/showthread.php?t=307686

    Last edited: May 22, 2009
  4. May 21, 2009 #3


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    Resistor color codes

    The inverse operation works also. Type this for input:
    Code (Text):
    resistor color 4.7k ohms
    ... and the output is an image of the resistor with the correct color bands:

    View the full W|A output here:
    http://www5f.wolframalpha.com/input/?i=resistor+color+4.7k+ohms&asynchronous=false&equal=Submit [Broken]

    Attached Files:

    Last edited by a moderator: May 4, 2017
  5. Oct 14, 2009 #4


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

  6. Apr 4, 2010 #5
  7. Apr 10, 2010 #6


    User Avatar
    Gold Member

    Check out the WolframAlpha app for the iPhone and iPod Touch. Its pretty awesome!
  8. Jul 13, 2010 #7
    Remember when the WA app cost $50? They thought because it's better than any scientific calculator could be, they could charge that much, but you know, no one would pay that much so they made it $2.
  9. Dec 20, 2010 #8
    is there any advantage over the ipod app vs the standard web version?
  10. Jun 17, 2011 #9
    Would you guys recommend wolfram alpha to a student who is interested in learning more about physics and modeling physics within computing systems? I have a small bit of experience with mathlab, and am hoping to be on the go as I do this (iPad, Android, etc.)
  11. Sep 14, 2011 #10
    I have "Algeo.apk" in my galaxy tab, it is a wonderful application in small scale.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook