Question

Which of the following types of interference will occur when the pulses in the figure above meet?

inteference.png


destructive

constructive

reflective

diffractive

Answer 1

I can't see the picture — could you describe the two pulses (are they both displaced upward, both downward, or is one up and the other down)?

Quick rule you can use:
- If the pulses have the same sign (both up or both down) they undergo constructive interference (their amplitudes add).
- If they have opposite sign (one up, one down) they undergo destructive interference (their amplitudes subtract; if equal in magnitude they cancel).
- "Reflective" and "diffractive" are different effects and are not the correct labels for the meeting of two pulses on the same medium.

If you tell me whether the pulses are in the same direction or opposite directions I’ll give the single correct choice.