Hello, From The West Midlands

[bigmoylan]

Hi All,

I found this forum on google and thought I would sign up as I may use this alot.

I'm currently studying Mechanical Engineering at College and we have to do an Electrical Sciences as one of the units.

I'm really quite struggling with my first assignment, the calculations I feel okay with.

but its the units and symbols etc. that I am struggling to come to terms with.

In one question I have to calculate the value of an equivalent capicitor which has the same reactance as my inductor and determine the energy stored within it if a p.d. of 6V is applied accross it.

I have in my notes that

XL=XC

XL= 2pifL

XC=1/(2pifL)

for my question I have XC=1/(2 x pi x 50 x 4.46(mH)) =

basicly i'm wondering is this the correct way for working out the first half of the question, are my units (mH) right for L and what units will the answer XC be in??

Many thanks to those who are able to help.

 

[m4tty]

Sorry I can't help you with this one but welcome to the forum mate

 

[bigmoylan]

No worries.

Cheers for the welcome.

I've had a nose around and favourited a few things I think may be useful in the future.

Really good forum!

 

[batty]

welcome not sure on your question as i probably didn't understand it when i did my training and there is no chance now. Some brighter sparks will hopefully help though.

 

[Sidewinder]

Welcome to the forum bigmoylan,

In your notes where it gives you XL = XC

What does it give you as the units?

Only you can tell us if the 4.46mH is correct for the value of your inductor, as this should be given in the question?

Check your formula for XC

 

[NozSpark]

If your inductive reactance and capacitive reactance are the same value then

Xc=Xl

Xc=1/(2 x pi x f x C) C=capacitance in Farads

Xl=2 x pi x f x L L=inductance in Henrys

So you have an inductance of 4.46mH and can work out Xl

Xl=2 x pi x 50 x 0.00446

Seeing as Xc is equal to Xl in your question you can now transpose the Xc formula

 

[bigmoylan]

Cheers for the welcomes and many thanks for the last post.

I was going about it completely wrong.

And that's opened my eyes.

Cheers

 

[bigmoylan]

Also a quicky.

Is f on htz?

 

[NozSpark]

f is frequency which is Hz

 

[bigmoylan]

Cheers

It's too late I think I'll try again in the morning.

Thanks for your help.