Chapter 11: Interference
11.1 Phenomenon of Interference: Coherent Sources
- Interference: When two or more waves superpose to give regions of maximum and minimum intensity.
- Constructive interference: Waves in phase → amplitude increases
- Destructive interference: Waves out of phase → amplitude decreases
- Coherent sources: Two sources that have constant phase difference and same frequency.
Example: Two speakers emitting sound of same frequency and fixed phase → certain points loud (constructive) and quiet (destructive).
11.2 Young’s Double Slit Experiment (YDS)
Important Short Questions and Answers in Short
Q1. Define interference.
👉 Superposition of two or more waves producing regions of maxima and minima.
Q2. What is constructive and destructive interference?
- Constructive → in phase → amplitude increases
- Destructive → out of phase → amplitude decreases
Q3. What are coherent sources?
👉 Sources with same frequency and constant phase difference.
✅ Formula Sheet (Quick Revision)
Numerical Examples
