Question

What are the path differences between wavelets arriving at C when \[\theta=0\]?

Options

• All path differences equal \[\frac{\lambda}{2}\]

• All path differences are zero

• All path differences equal \[\lambda\]

• The path differences increase as \[n\] increases

Answer 1

Equal distances from the secondary sources to C give zero path difference. The wavelets therefore arrive at C in phase.