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RMS Value

Problem-Solving Strategy for solving the RMS Values

STEP 1. At first, the rms value of voltage is as follows: $V_{rms}=\sqrt{\frac{1}{T}\intop\nolimits_{t_0}^{t_0+T}v^2(t) dt}$

STEP 2. Similarly, the rms value of current is as follows: $I_{rms}=\sqrt{\frac{1}{T}\intop\nolimits_{t_0}^{t_0+T}i^2(t) dt}$

PROBLEM:

Basic Engineering Circuit Analysis Problem 9.71
Note: This post is based on Irwin's Basic Engineering Circuit Analysis 11th ed.
If there are any errors in solution, please let me know in the comments

SOLUTION:

The waveform is periodic with period $T=6s$. The equation for the voltage in the time frame $0\leq t\leq 6s$ is

$\begin{Bmatrix}-4V &(0 \leq t<2s)\\(-2t+8)V &(2s \leq t<4s)\\0V &(4s \leq t<6s)\end{Bmatrix}$

The rms value is

$V_{rms}=\sqrt{\frac{1}{6}[\intop\nolimits_{0}^{2}(-4)^2 dt+\intop\nolimits_{2}^{4}(-2t+8)^2 dt+\intop\nolimits_{4}^{6}(0)^2 dt]}=2.667V$

Related posts: Instantaneous Power
                   Maximum Average Power Transfer
                   Complex Power

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