Question

A frequency counter needs to measure a frequency of 15 Hz. Its signal gating time is 2s. What is the percentage accuracy of the counter, taking into account the gating error?
1. 3.33%
2. 13.33%
3. 98.67%
4. 96.67%

Answer 1

Correct Answer - Option 4 : 96.67%

Gating signal determines the length of time during which the counters are allowed to totalize the pulses separated by the period of the original input signal.

\(f = \frac{N}{t}\)

Where t is gating time

⇒ N = ft = 15 × 2 = 30

Percentage accuracy of the counter \( = \frac{{N - 1}}{N} \times 100 = \frac{{30 - 1}}{{30}} \times 100 = 96.67\;\% \)