# Find Phasor

Discussion in 'Homework Help' started by Marco foschi, Mar 9, 2015.

1. ### Marco foschi Thread Starter New Member

Mar 4, 2015
4
0

The result for this problem is: -12.5 Cos(2t-53.13°) A

I've found :
Zc=-5J
Zl= J
I(2)= -5/2 = -2,5 A over 2 ohm resistor

Then I've found Vc+Vl+Vr(2ohm) = ((-5+1)*-2.5)-5 =-15V

I found current through 1ohm resistor = -15V/1= -15 A

So I have -15-(-2.5) = -12.5 A

Is it correct my procedure?
How can I find angle of 53.13° ??

Thanks

2. ### Dodgydave AAC Fanatic!

Jun 22, 2012
5,003
745
what is the frequency of the voltage?

3. ### t_n_k AAC Fanatic!

Mar 6, 2009
5,448
782
The question attached in post #1 shows it to be 2 radians/sec.

4. ### Dodgydave AAC Fanatic!

Jun 22, 2012
5,003
745
Thats about 0.31Hz, at that frequency the capacitor will have a reactance of 5.1 Meg ohms, the inductor will be 1 ohm, i dont think any current will flow in the series circuit.

5. ### t_n_k AAC Fanatic!

Mar 6, 2009
5,448
782
Check the capacitor value in the circuit. It's 0.1 Farad not uF. Wouldn't that give Xc=5 ohms ?

6. ### shteii01 AAC Fanatic!

Feb 19, 2010
3,398
497
Phasor contains magnitude and angle. I don't see where you are using phasors. That is why you don't have any way to find the angle.