In the following statements, tick ‘T’ against those which are true, and ‘F’ against those which are false.(a) Sound cannot travel in vacuum.(b) The number of oscillations per second of a vibrating object is called its time period.(c) If the amplitude of vibration is large, sound is feeble.(d) For human ears, the audible range is 20 Hz to 20, 000 Hz.(e) The lower the frequency of vibration, the higher is the pitch.(f) Unwanted or unpleasant sound is termed as music.(g) Noise pollution may cause partial hearing impairment.
Fill in the blanks with suitable words.(a) Time taken by an object to complete one oscillation is called ______.(b) Loudness is determined by the ______ of vibration.(c) The unit of frequency is ______.(d) Unwanted sound is called ______.(e) Shrillness of a sound is determined by the ______ of vibration.
The sound from the 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 ?
Your parents are going to buy a house. They have been offered one on the roadside and another three lanes away from the roadside. Which house would you suggest your parents should buy? Explain your answer.
Lightning and thunder take place in the sky at the same time and at the same distance from us. Lightning is seen earlier and thunder is heard latter. Can you explain why?
