ac electric math help
 

i cant read my formula in my notes on how to do this problem here is the problem
the peak voltage of a sine wave is 10v. what is its instantaneous value at 30 degrees and at 40 degrees?
anyone?

o_O

Who did what to who now?

i got the question from my book

you did waht at 30 degrees?

Get the answer from the back of the book...page 327

-- Rogue

i tryed just a glossry and index

Re: ac electric math help
 

You need to know the amplitude and frequency of the wave before you can do the calcs and this is assuming that your offset is zero.

Re: ac electric math help
 

I'd have to pull my old college books out.....and I'm at work right now......I can give you a rough idea of what your answers would be:

At 0, 180 and 360, your instantaneous voltage is 0, right?

At 90° you're 10v peak (assuming 20v p-p?), so at 30° you should be .3 of 10, or 3v. 40° would be 4v. Actually a pretty simple problem.

Re: ac electric math help
 

Doesn't quite work that way Bill...for pete's sake you are a laser technician! :shock: You are right on the quadrant angle values.

You have to know the cycle time to know the phase angle. The top (or bottom) of a sine wave is a parabola based on the amplitude and half-cycle time, therefor it is not a linear relationship for amplitude vs. angle.

Yes, I realize I am telling everything but how to find the answer. I would have to look it up either in a AC circuits or a trig textbook.

Jay

Shit it's been a long time. I got my degree in 92! Gimme a break. I don't have to figure anything any more. I just use an oscilloscope now!