Below is a concise list of key definitions from Chapter 8: Waves

Below is a concise list of key definitions from Chapter 8: Waves of the 11th Class Physics syllabus for the Federal Board of Intermediate and Secondary Education (FBISE), aligned with the National Book Foundation (NBF) curriculum. These definitions cover the essential concepts related to waves as typically presented in this chapter.

1. Wave: A disturbance that transfers energy through a medium or space without transferring matter.
2. Mechanical Wave: A wave that requires a medium (solid, liquid, or gas) to propagate (e.g., sound waves, water waves).
3. Electromagnetic Wave: A wave that can propagate through a vacuum, consisting of oscillating electric and magnetic fields (e.g., light, radio waves).
4. Transverse Wave: A wave in which the particles of the medium vibrate perpendicular to the direction of wave propagation (e.g., waves on a string).
5. Longitudinal Wave: A wave in which the particles of the medium vibrate parallel to the direction of wave propagation (e.g., sound waves).
6. Crest: The highest point of a transverse wave above the equilibrium position.
7. Trough: The lowest point of a transverse wave below the equilibrium position.
8. Compression: A region in a longitudinal wave where particles are closest together, resulting in high pressure.
9. Rarefaction: A region in a longitudinal wave where particles are farthest apart, resulting in low pressure.
10. Wavelength (λ): The distance between two consecutive points in a wave that are in phase (e.g., crest to crest), measured in meters.
11. Amplitude (A): The maximum displacement of a wave particle from its equilibrium position, measured in meters.
12. Frequency (f): The number of complete wave cycles passing a point per unit time, measured in hertz (Hz).
13. Time Period (T): The time taken for one complete wave cycle, given by T = 1/f, measured in seconds.
14. Wave Speed (v): The speed at which a wave propagates through a medium, given by v = fλ, measured in meters per second (m/s).
15. Progressive Wave: A wave that travels continuously in a medium, transferring energy away from the source.
16. Stationary Wave (Standing Wave): A wave formed by the superposition of two identical waves traveling in opposite directions, appearing to vibrate in place with fixed nodes and antinodes.
17. Node: A point in a standing wave where the displacement is always zero due to destructive interference.
18. Antinode: A point in a standing wave where the displacement is maximum due to constructive interference.
19. Superposition Principle: When two or more waves overlap, the resultant displacement at any point is the vector sum of the displacements of the individual waves.
20. Interference: The interaction of two or more waves passing through the same region, resulting in constructive or destructive effects.
21. Constructive Interference: The superposition of waves where crests (or troughs) align, resulting in a larger amplitude.
22. Destructive Interference: The superposition of waves where a crest aligns with a trough, resulting in reduced or zero amplitude.
23. Beats: The periodic variation in amplitude resulting from the superposition of two waves with slightly different frequencies.
24. Doppler Effect: The change in frequency or wavelength of a wave observed when the source and observer are in relative motion.
25. Fundamental Frequency: The lowest frequency at which a system (e.g., a string or air column) can vibrate, also called the first harmonic.
26. Harmonics: Integer multiples of the fundamental frequency, producing standing wave patterns in vibrating systems.
27. Resonance: The phenomenon where a system vibrates with maximum amplitude when driven at its natural frequency.

These definitions encapsulate the core concepts of waves from Chapter 8 of the FBISE 11th Class Physics curriculum. If you need further explanation or additional terms, please let me know!