When the frequency of a DC source is doubled, the inductive reactance XL.
Correct answer: D. None
- A. Doubles
- B. Quadrupled
- C. Tripled
- D. None
Explanation
A DC source has a frequency of zero. The concept of "doubling" a zero frequency is not meaningful. Inductive reactance (XL = 2πfL) is zero for a DC source and remains zero.
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Alternating current varies periodically, so phase relationships become essential when current passes through a resistor, capacitor or inductor. The chapter distinguishes resistance from capacitive and inductive reactance, explains phase lead and lag, and connects changing electric and magnetic fields with the production and properties of electromagnetic waves.
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