Posts

Showing posts from August, 2021

Sound (part -4) class 8

Image
  SOUND Characteristics of sound Q.8. Define the following terms: Frequency, time-period and amplitude. Ans. Frequency : The number of oscillations per second is called the frequency of oscillation. Frequency is expressed in hertz. Its symbol is Hz. Time-period : The time period is  the time taken by the oscillating object to complete oscillation. It is expressed in seconds.   Amplitude : the amount of maximum displacement of vibrating particles of the medium from their mean position is called the Amplitude of oscillation. It is also known as size of vibration. The SI unit of amplitude is  the meter. Q.9. A pendulum oscillates 40 times in 4 seconds. Find its time period and frequency. Q.10. The sound from a mosquito is produced when it vibrates its wings at an average rate of 500 vibrations per second. What is the time period of the vibration? Q .11. How c an we differentiate sounds on the basis of their amplitudes? Ans. Th