Peak voltage from oscilloscope y-gain

Steps:

• y-gain of 2 V/cm means 2 V per vertical cm on screen.
• For AC voltage, maximum value is peak from zero line to crest.
• Waveform peak deflection is 2 cm (implied by display).
• Peak voltage = 2 cm × 2 V/cm = 4 V.

Why B is correct:

• Peak voltage equals deflection height times y-gain, per oscilloscope calibration.

Why the others are wrong:

• A. Assumes 1 cm deflection.
• C. Assumes 4 cm deflection.
• D. Assumes 6 cm deflection.

Final answer: B