Phase Difference from Time Shift on Graph

Steps:

• Determine the period T of the waves from one full cycle on the graph.
• Identify the horizontal time shift δt between corresponding points (e.g., peaks) of the two waves at P.
• Calculate phase difference φ = (δt / T) × 360°.
• The graph shows δt = T/8, so φ = 45°.

Why B is correct:

• Phase difference is defined as the angular shift φ = (δt / T) × 360°, matching 45° for the observed time delay.

Why the others are wrong:

• A: 0° implies identical waves with no shift, but graph shows offset.
• C: 90° requires δt = T/4, larger than observed.
• D: 180° requires δt = T/2, half-period reversal not present.

Final answer: B