Path difference

• What is path difference in wave propagation?

  Difference in lengths of two paths
• If path A is 5 meters and path B is 3 meters, what is the path difference?

  2 meters
• How is phase defined in a wave?

  Position within a wave represented as an angle
• What type of wave is referenced in the study material?

  Cosine wave
• What does phase difference represent in wave interactions?

  Angular equivalent to path difference
• How can phase difference be calculated?

  As a fraction of the wave multiplied by 360 degrees
• What is the relationship between phase difference and wavelength?

  Phase difference equals path difference divided by wavelength
• What is the formula for wave speed?

  Speed = frequency multiplied by wavelength
• What happens when two waves are in phase?

  They produce constructive interference
• What is the result of superposing two in-phase waves?

  Higher displacement wave
• What is the phase difference when two waves are out of phase by 180 degrees?

  They produce destructive interference
• How can phase differences of 90 degrees be expressed?

  As 450 degrees or 810 degrees
• What does subtracting an integer number of 360 degrees from a phase difference indicate?

  Same influence remains
• If the phase difference is 120 degrees, how do you find the path difference?

  Use the formula: path difference = phase difference × wavelength / 360
• What is the path difference if the wavelength is 2 meters and phase difference is 120 degrees?

  $\frac{2 \text{ m} \times 120}{360} =$$\frac{2}{3} \text{ m} \approx 0.67 \text{ m}$
• If AC is 100 meters, what is one possible value for BC?

  100.67 meters
• What is another possible value for BC if AC is 100 meters?

  102.67 meters
• What are the key concepts related to path and phase differences in wave propagation?

  • Path difference: Difference in lengths of two paths
  • Phase: Position in a wave as an angle
  • Phase difference: Angular equivalent to path difference
  • Constructive interference: In-phase waves add up
  • Destructive interference: Out-of-phase waves cancel out
• How do you determine possible values for BC given AC and wavelength?

  1. Calculate path difference using phase difference.
  2. Use geometry to find BC.
  3. Consider adding or subtracting wavelengths.