The distance between two consecutive crests in a wave is known as:

$(i)$ Even if a loud explosion were to take place at any place on the moon,it would not be heard at a nearby point. Give reason.
$(ii)$ Explain in brief the dependence of speed of sound on the nature of the material medium and temperature.
$(iii)$ Identify the two factors on which the loudness of sound depends.

What change,if any,would you expect in the characteristics of musical sound when we increase $(i)$ its frequency and (ii) its amplitude?

The stem of a tuning fork is pressed against a table top. Answer the following questions: $(i)$ Would the above action produce any audible sound? $(ii)$ Does the above action cause the table to set into vibrations? $(iii)$ If the answer above is yes,what type of vibrations are they? $(iv)$ Under what conditions does the above action lead to resonance?

State any two characteristics of a wave motion.

How does a stretched string,on being set into vibration,produce an audible sound?