Question

(i) Which point is crest and which point is trough?
(ii) If the distance between two consecutive troughs is 5 mm then what is the wavelength of the wave?
(iii) What is the relation between frequency and time period of a wave?

Answer 1

Crest, trough, wavelength, frequency and time period

Explanation:

(i) A crest is the point on a sound wave with the maximum value of upward displacement within a cycle. A crest is a point on a surface wave where the displacement of the medium is at a maximum. A trough is the opposite of a crest, so the minimum or lowest point in a cycle.

(ii) The distance between two consecutive troughs will be one cycle. So the distance travelled by sound in one cycle is its wavelength of the wave. Wavelength = 5mm

(iii) Frequency is inversely proportional to time period. Time period is the time taken to complete a cycle of any function while frequency is the number of times a cycle is completed each second.