# i don't understand what it says...

Discussion in 'Homework Help' started by arko_buet09, Mar 26, 2011.

1. ### arko_buet09 Thread Starter New Member

Mar 26, 2011
5
0
i am solving the alternating current circuits by corcoran and having a little bit problem with language things(English is not my first language)
a problem says ..
find the instantaneous value of a sinusoidal alternating current having a maximum value of 90 amperes, 60 degree after the currnet passes through its zero value going positive 225 degree after the current passes through its zero value going positive.

2. ### hgmjr Moderator

Jan 28, 2005
9,030
214
The problem statement appears to provide all of the information needed to find the solution.

Since the problem is dealing with a sinusoidal current waveform then you may want to consider calling on your knowledge of the sine-function to derive the value of current at the two given angles. Remember that sine of the angle zero is zero and then go from there.

At least take a shot at a solution and post it here.

hgmjr

3. ### Georacer Moderator

Nov 25, 2009
5,142
1,266
Remember that the formula of your current is
$I=I_0 \sin (\phi)$

$i_0$ is the maximum value of the current.
$\phi$ is expressed in degrees and is the current angle of the current and is equal to $\omega \cdot t$.

Last edited: Mar 26, 2011
4. ### Georacer Moderator

Nov 25, 2009
5,142
1,266
Thanks for the correction. I usually read my posts once before submitting them. I corrected it myself too.

5. ### arko_buet09 Thread Starter New Member

Mar 26, 2011
5
0
yeah! i solved it. i was a little bit confused with the phi angle, here in the formula mentioned.
the ans was 77.94 A for the 60 degree

thanks guys;