Matching CRO waveforms to time-base periods

Steps:

• Identify the period of each waveform from the screen display (distance between peaks).
• Use time-base setting to convert screen distance to actual time (period T = distance × time/div).
• Calculate frequency f = 1/T for each CRO.
• Compare frequencies to determine which screens show the same waveform characteristics.

Why A is correct:

• Screens 1 and 2 have matching periods when scaled by their time-base settings, per the CRO formula T = horizontal distance × time per division.

Why the others are wrong:

• B: Screens 1 and 3 yield different periods due to mismatched time bases.
• C: Screens 1 and 4 show inconsistent frequencies from unequal scaling.
• D: Screens 2 and 3 have non-matching waveform periods after time-base adjustment.

Not enough information: Waveform details and exact time-base values are not provided.

Final answer: A