Engineering Board Exam Reviewer · RL Circuits · hard
A series RL circuit has R=470, and L=100 mH. At what frequency does the current lag the source voltage by 45°?
- 0.748 kHz
- 4.7 kHz
- 0.374 kHz
- 1.5 kHz
Answer
A. 0.748 kHz
Solution
The angle is 45° when XL=R: 2π fL=R f=R/2π L=470/2π(0.1)=748 Hz.
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