Finding voltage across elements in phasor diagram,

Click For Summary
SUMMARY

The discussion focuses on calculating voltage across elements in a phasor diagram, specifically addressing the voltage expression v(t) = 5cos(2t - 112°). The user successfully determined the current as 1.386 < -56.5°, but encountered difficulties in deriving the correct voltage across the capacitor. The user attempted to use the formula V = IZ, resulting in an incorrect voltage expression of 4.14cos(2t + 33.5°). The conversation highlights the importance of distinguishing between RMS and peak values in phasor analysis.

PREREQUISITES
  • Understanding of phasor diagrams and their components
  • Knowledge of AC circuit analysis techniques
  • Familiarity with complex numbers in electrical engineering
  • Concept of RMS (Root Mean Square) vs. peak values in voltage and current
NEXT STEPS
  • Study phasor analysis techniques in AC circuit theory
  • Learn how to apply the V = IZ formula correctly in phasor calculations
  • Research the differences between RMS and peak values in electrical signals
  • Explore examples of voltage and current calculations in capacitive circuits
USEFUL FOR

Electrical engineering students, circuit designers, and professionals working with AC circuits who need to understand phasor analysis and voltage calculations.

checkedcherry
Messages
1
Reaction score
0
Finding voltage across elements in phasor diagram, URGENT!

Hi there, first time posting here, just caught up on a question with no worked solutions and it's driving me crazy!

I've attached the question below,and the answer to b is v(t)= 5cos(2t-112).
I can do part a but am struggling on part b nothing I try seems to come up with 112 degrees :(

Anyway, here's my (very poor) attempt:

I found the current to be
1.386 < -56.5 degrees i.e 1.386 cos (2t-56.5)

and then tried to find voltage across the capacitor using V=IZ to get 4.14cos(2t+33.5)
which didn't seem right...so can anyone point me in the right direction?

Thanks in advance!
 

Attachments

  • phasor.png
    phasor.png
    7.2 KB · Views: 532
Physics news on Phys.org


Clue: RMS value (root mean square) vs. peak value...

1.386 < -56.5 degrees ≠ 1.386 cos (2t-56.5)
 

Similar threads

Phasor diagrams for RLC circuit and resonant frequency
  • · Replies 3 ·
Replies
3
Views
5K
Find phasor voltages, current, phasor diagrams
  • · Replies 13 ·
Replies
13
Views
37K
Adding Two Waveforms to find the final Phasor
  • · Replies 4 ·
Replies
4
Views
2K
Finding Steady State Amplitude of Voltage Across Load Resistor
  • · Replies 3 ·
Replies
3
Views
3K
Engineering RLC circuit -- determine the voltage across each element
  • · Replies 8 ·
Replies
8
Views
3K
Engineering AC Circuit Phasors: Find I1, I2, I3
  • · Replies 26 ·
Replies
26
Views
3K
Engineering Electrical Engineering - AC Circuits Phasors
  • · Replies 2 ·
Replies
2
Views
2K
Find Power w/ Phasors: V=IZ in Electrical Engineering
  • · Replies 2 ·
Replies
2
Views
4K
Engineering Phasor Diagram RLC Series AC Circuit
  • · Replies 11 ·
Replies
11
Views
9K
Obtain Expression For Voltage Across Capacitor
  • · Replies 2 ·
Replies
2
Views
2K