The reactance offered by a capacitor to alternating current of frequency 50 Hz is 20 Q. If frequency is increased to 100 Hz, reactance becomes_______ohms?
Correct answer: C. 10
- A. 2.5
- B. 5
- C. 10
- D. 15
Explanation
Capacitive reactance is Xc = 1/(2πfC), so it is inversely proportional to frequency. Doubling the frequency from 50 Hz to 100 Hz halves 20 Ω to 10 Ω.
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