Okay I may be wrong with this, but it seems there is an error in
AC power
http://www.allaboutcircuits.com/worksheets/acpower.html
Question 31, part 2.
Here are my calculations for working out the line current:
1/Xc + 1/Za = 1 / Ztot
(2*60*pi*270x10^-6)<-90 + 1/(5<34) = 1/Ztot
Z tot = 1 / ((2*60*pi*270x10^-6)<-90 + 1/(5<34))
Z tot = 3.698 < 52.183
This gives a line current of V/Z = I
I = 240 / (3.698 < 52.183)
I = 64.8999 < -52.18
The supposed answer is I line = 39.87 A
It seems as if calculations went like this:
1/Xc + 1/Za = 1 / Ztot
(2*60*pi*270x10^-6)<90 + 1/(5<34) = 1/Ztot **Note 90, not -90
Z tot = 1 / ((2*60*pi*270x10^-6)<90 + 1/(5<34))
Z tot = 6.02 < 3.47
I = V / Z
I = 39.87 < - 3 .47.
As far as I'm aware a capacitor with value 10 F has
Xc = (1 / (2pi*f*10)) < -90.
Please let me know if this is infact an error in the answer, or an error on my part.
Regards,
Steve
AC power
http://www.allaboutcircuits.com/worksheets/acpower.html
Question 31, part 2.
Here are my calculations for working out the line current:
1/Xc + 1/Za = 1 / Ztot
(2*60*pi*270x10^-6)<-90 + 1/(5<34) = 1/Ztot
Z tot = 1 / ((2*60*pi*270x10^-6)<-90 + 1/(5<34))
Z tot = 3.698 < 52.183
This gives a line current of V/Z = I
I = 240 / (3.698 < 52.183)
I = 64.8999 < -52.18
The supposed answer is I line = 39.87 A
It seems as if calculations went like this:
1/Xc + 1/Za = 1 / Ztot
(2*60*pi*270x10^-6)<90 + 1/(5<34) = 1/Ztot **Note 90, not -90
Z tot = 1 / ((2*60*pi*270x10^-6)<90 + 1/(5<34))
Z tot = 6.02 < 3.47
I = V / Z
I = 39.87 < - 3 .47.
As far as I'm aware a capacitor with value 10 F has
Xc = (1 / (2pi*f*10)) < -90.
Please let me know if this is infact an error in the answer, or an error on my part.
Regards,
Steve