- #1
jitznerd
- 10
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Homework Statement
An a.c. voltage, V, comprises of a fundamental voltage of 100V rms at a frequency of 120Hz, a third harmonic which is 20% of the fundamental, a 5th harmonic which is 10% of the fundamental and at as phase angle of 1.2 radians lagging.
1. Write down an expression for the voltage waveform.
2. Determine the voltage at 20ms.
Homework Equations
The Attempt at a Solution
Im not sure if this is right and would appreciate if someone could take a quick look over it please.
1. I have the fundamental (Vrms x √2) at 141.4v at 120Hz
making 3rd harmonic (20% of 141.4) = 28.3v at 360Hz
and the 5th harmonic (10% of 141.4v) = 14.1v at 600Hz
Therefore V=141.1 sin (2∏ft) + 28.3 sin (2∏ft) + 14.1 sin (2∏ft-1.2)
2. Using the equation above and inserting 20ms for "t" I got the following voltages
4.05v + -1.16v(?) + 74.15v = 77.04v
Any help would be appreciated thanks