- #1
FrogPad
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I can't believe I'm asking this, but for some reason I cannot remember this.
Here is the basic question from my power class.
Q: What is the phase difference between:
[tex] v=V_{max}\sin \omega t [/tex]
[tex] i = I_{max} \cos( \omega t - 30) [/tex]
So we simply rewrite [itex] v [/itex] as: [itex] v = V_{max} \cos ( \omega t + 90 ) [/itex]
Now my first thought to find the phase difference is the following. The voltage is shifted left by 90 degrees, and the current is shifted right by 30 degrees. Thus the difference is simply, 90 + |-30| = 120.
Then I thought for a second, well if we draw the unit circle, the voltage would be rotated 90 degrees counter clockwise, and the current would be rotated clockwise 30 degrees. So the angle between them would be 240 degrees.
Would someone please tell me what I'm missing here. Thanks.
Here is the basic question from my power class.
Q: What is the phase difference between:
[tex] v=V_{max}\sin \omega t [/tex]
[tex] i = I_{max} \cos( \omega t - 30) [/tex]
So we simply rewrite [itex] v [/itex] as: [itex] v = V_{max} \cos ( \omega t + 90 ) [/itex]
Now my first thought to find the phase difference is the following. The voltage is shifted left by 90 degrees, and the current is shifted right by 30 degrees. Thus the difference is simply, 90 + |-30| = 120.
Then I thought for a second, well if we draw the unit circle, the voltage would be rotated 90 degrees counter clockwise, and the current would be rotated clockwise 30 degrees. So the angle between them would be 240 degrees.
Would someone please tell me what I'm missing here. Thanks.