A CRO trace shows five complete periods across 10.0 divisions. Time-base=0.20 ms div⁻¹ and y-gain=0.50 V div⁻¹. The trace extends 4.8 divisions peak-to-peak about its midline. Determine frequency and voltage amplitude. Explain why measuring five periods is preferable to one, and why this voltage is not automatically a sound displacement amplitude.

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T=(10.0 × 0.20 ms)/5=0.40 ms, f=2500 Hz. Amplitude=(4.8/2) × 0.50=1.2 V. The multi-period span reduces fractional reading uncertainty; physical sound amplitude needs sensor calibration. Compute total time 2.0 ms and divide by five. Convert T to 4.0 × 10⁻⁴ s and invert: 2.5 × 10³ Hz. Halve peak-to-peak divisions, then multiply by y-gain. Explain reduced fractional grid-reading uncertainty. Distinguish voltage sensitivity from microphone displacement/pressure calibration.

Read the calibrated screen, not just divisions

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