Characteristics of Waves G10-7-2 PDF

**7.3 CHARACTERISTICS OF WAVES** This section will discuss some quantities of periodic waves. **Wave Crest and Trough of Periodic Waves** The highest and the lowest points (Figure 7.6) which show the maximum displacement of vibrating particle from its rest position (or) equilibrium line are calle...

**7.3 CHARACTERISTICS OF WAVES** This section will discuss some quantities of periodic waves. **Wave Crest and Trough of Periodic Waves** The highest and the lowest points (Figure 7.6) which show the maximum displacement of vibrating particle from its rest position (or) equilibrium line are called wave crest and wave trough respectively. The arrows indicate the direction of displacement of the vibrating particle. Wavelength (2): The distance between any two consecutive wave crests (or) two consecutive wave troughs is called wavelength. The unit of wavelength in SI unit is metre (m). Generally the wavelength is the distance between two nearest points of same phase. Frequency (f): The number of complete waves passing a point per second is called frequency) of waves. The frequency of the wave depends on the vibrating source. The number of oscillation of a vibrating source in one second is also called frequency. The SI unit of frequency is hertz (Hz). One hertz is equal to one complete cycle per second. at/=0 s me second at/= 1 s f = 4 Hz Figure 7.7 Frequency of a periodic wave (four complete waves pass a point in one second) Period (T): The time taken by the wave to travel the distance between any two consecutive wave crests (or) the time required for one complete vibration is called period of a wave. The unit of period is the second (s). The period is the reciprocal or inverse of the frequency. Thus, T= at 1=0s at 1=Ts Textbook Figure 7.8 Period of the wave задають Amplitude: The amplitude of a wave is the maximum value of displacement of vibrating particle. It can be seen on the wave graph shown in Figure 7.6 as the perpendicular distance from the equilibrium line to the wave crest (or) trough. Velocity of Wave (v): Velocity of wave is the speed with which a wave crest travels. The unit of wave velocity is metre per second (m s1). Most of the periodic waves are represented by sine (or) cosine graphs. Therefore they can be called sine waves. The relationship between the frequency, wavelength and velocity of a periodic wave can be obtained by **distance moved\>\>** velocity = **time taken** A complete wave travels through the distance equal to its wavelength in time period T. velocity **wavelength period** Since, **2** V= *T* 1 T= **Reviewed Exercise** v=f2 Write down the relation between period and frequency. Explain it.