Why Does My Inductive Impedance Calculation Seem Incorrect?

[thepipersson80]

Hi guys,

Firstly I apologise that I'm even asking this... I have gone over it so many times now I don't know what to believe is the right answer, can someone please help me out and let me know where I'm going wrong PLEASE

Ok so first is the inductive impedance

Z= SQRT R^2 + (WL)^2

R = 2.7*10^6 2.7MΩ
W= 2piF = 2pi*10 2pi*10Hz
L= 300*10^-3 300mH

R^2 = 7.29*10^12
WL = 18.84955592 WL^2 = 355.3057584
R^2+WL^2 = 7.29*10^12 + 355.3057584 =7.29*10^12

How can that be right? I may of well just squared R to start with... so what am I doing wrong?

Second,

Impedance in RLC circuits

Z= SQRT R^2 +(Xl - Xc)2

W = 2piF = 628318.5307

F = 100*10^3 = 100000
C = 300*10^-6 = 3*10^-4
L = 300*10^-3 = 0.3
R = 2.7*10^6 = 2700000
Xl = WL = 188495.5592
Xc = 1/WC = 5.30516477*10-3

so R^2 +(Xl - XC)^2 = 7.325530574*10^12 and to me that just does not seem the right answer??

Can you guys see where I would be going wrong? and if so how do I put it into my calculator?
Many thanks

 

[Integral]

Why do you think you are doing something wrong? The reactance factors are frequency dependent. What you have learned is that at 10Hz (a very low frequency) the reactive elements have very little effect. Try higher frequencies.

Side note. Do NOT copy every digit off of your calculator display. It would do you much good to find a explanation of significant digits. This bit of work will save you time and effort in the future.

 

[thepipersson80]

I just don't think it's right? and when I go to a online calculator I get different answers.

My maths is not that great to say the least, so to be honest I don't know what is significant and what isn't (sorry)

 

[NascentOxygen]

I just don't think it's right? and when I go to a online calculator I get different answers.

My maths is not that great to say the least, so to be honest I don't know what is significant and what isn't (sorry)

Don't forget to take the square root, to end up with Z.

 

[CellCoree]

Dear fellow scientist,

It looks like you may be having some trouble with your calculations for inductive and RLC circuits. First, let's address the inductive impedance equation. The formula is correct, but it seems like you may have made a mistake when plugging in your values. It is important to remember to use the correct units when inputting values into equations. For example, in the R^2 calculation, you wrote 7.29*10^12, but the correct answer should be 7.29*10^14 since you are multiplying 2.7*10^6 by itself. Similarly, in the WL^2 calculation, the correct answer should be 355.3057584*10^6, as you are multiplying 18.84955592 by itself. When adding these two values together, you should get 7.29*10^14 + 355.3057584*10^6 = 7.29*10^14 + 3.553057584*10^11 = 7.29*10^14 + 355.3057584*10^6 = 7.293553057584*10^14. This is where you may have made a mistake, as you wrote 7.29*10^12 instead of 7.293553057584*10^14.

Moving on to the impedance in RLC circuits, the equation you have written is correct. However, it seems like you may have made a mistake when calculating Xl and Xc. For Xl, you wrote WL = 188495.5592, but the correct answer should be 188495.5592*10^3, as you are multiplying 2pi*10 by 300*10^-3. Similarly, for Xc, the correct answer should be 5.30516477*10^-1, as you are dividing 1 by 2pi*10*3*10^-4. When you plug these values into the equation, you should get R^2 +(Xl - XC)^2 = 7.29*10^14 + (188495.5592*10^3 - 5.30516477*10^-1)^2 = 7.29*10^14 + (188495.5592*10^3 - 5.30516477*10^-1)^2 = 7.