CRO Measurements for Sound Frequency and Amplitude

Steps:

• Convert time-base to seconds per cm: 0.5 ms/cm = 0.0005 s/cm.
• Measure horizontal distance for one full cycle on trace (e.g., 6 cm), so period T = 6 × 0.0005 s = 0.003 s.
• Calculate frequency f = 1/T = 1/0.003 ≈ 333 Hz (≈330 Hz).
• Measure vertical peak-to-peak deflection (e.g., 3 cm), so amplitude = 3 × 0.2 V/cm = 0.6 V.

Why A is correct:

• Matches calculated values using CRO formula f = 1/(distance × time-base) and amplitude = deflection × sensitivity.

Why the others are wrong:

• B: Frequency too high (implies shorter period, e.g., 3 cm cycle).
• C: Frequency too high (ignores full cycle distance).
• D: Both frequency too high and amplitude double (e.g., peak instead of peak-to-peak).

Final answer: A