NCERT Solutions for Class 11 Physics Chapter 15 - Waves

The concept of waves and its different types are very important for future topics. We will read about transverse waves and longitudinal waves with the help of equations and illustrations. We will also look at the displacement relation in a progressive wave. The chapter also teaches us how to calculate the speed of a traveling wave. The principle of superposition of waves along with the concept of reflection of waves has also been illustrated. The chapter finally concludes by giving us a brief about beats and the Doppler Effect in waves.

• Matters that move without actual physical transfer or flow of matter as a whole are called waves.
• These waves also transport energy.
• The chapter also teaches us about transverse and longitudinal waves as per their oscillations and their waves' direction.
• Certain equations in the chapter have also been explained in terms of amplitude and phase.
• We also read about angular waves and angular frequency in the chapter.
• The chapter also teaches us how to calculate the speed of a transverse wave on a stretched string.
• Consequently, we also study the speed of a longitudinal wave, or, the speed of sound.
• The chapter then talks about the concepts of reflection and refraction of waves.
• Within these concepts, we are introduced to standing waves and normal modes.
• We will also study resonance again in this chapter.
• The chapter also introduces us to the first and second harmonic.
• Beats is a phenomenon which arises out of the interference of waves.
• Motion related frequency change of a sound is called the Doppler Effect.
• We study this effect in situations like - when the source is stationary and the observer moving, and when the source is moving and the observer stationary.
• The chapter concludes by explaining the situation when both the source and the observer are moving.