(a) Time taken by an object to complete one oscillation is called time period.
(b) Loudness is determined by the amplitude of vibration.
(c) The unit of frequency is hertz (Hz).
(d) Unwanted sound is called noise.
(e) Shrillness of a sound is determined by the frequency of vibration.
Select the correct word from the following list and fill in the blanks.
float, water, crop, nutrients, preparation
| A | B | ||
|---|---|---|---|
| (i) | Kharif crops | (a) | Food for cattle |
| (ii) | Rabi crops | (b) | Urea and super phosphate |
| (iii) | Chemical fertilizers | (c) | Animal excreta, cow dung urine and plant waste |
| (iv) | Organic manure | (d) | Wheat, gram, pea |
| (e) | Paddy and maize | ||
Sound is a vibration that propagates the mechanical wave of displacement and pressure, through a medium can be of any matter. In other words, the sound is the thin line between Music sound and Noise.
Sound can be divided into two types depending on its frequency. The following are:-