The period of a signal is 100 ms. What is its frequency in kilohertz?
2020
The period of a signal is 100 ms. What is its frequency in kilohertz?
Answer: C. 10-2 — Concept: Frequency f and period T are reciprocals, so f = 1/T. When T is measured in seconds, f is in hertz; 1 kHz = 1000 Hz. Application: Convert the period…
- A.
10
- B.
10-1
- C.
10-2
- D.
10-3
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Correct answer: C
Concept: Frequency f and period T are reciprocals, so f = 1/T.
When T is measured in seconds, f is in hertz; 1 kHz = 1000 Hz.
Application:
Convert the period to seconds: T = 100 ms = 100 × 10-3 s = 0.1 s.
Apply the reciprocal relation: f = 1/T = 1/0.1 s = 10 Hz.
Convert hertz to kilohertz: 10 Hz ÷ 1000 = 0.01 kHz = 10-2 kHz.
Cross-check: At 10 Hz, ten cycles take 10 × 0.1 s = 1 s, which agrees with a period of 0.1 s per cycle.
Result: The frequency is 10-2 kHz (0.01 kHz).
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