Why are musical instruments provided with more than one string?

Explain, why stringed musical instruments, like the guitar, are provided with a hollow box

A sound produced by one musical instruments is 20dB more intense as compared to the sound by another instrument. What are their relative powers?

STATEMENT-1: All instrumental errors are random errors. STATEMENT-2:Some of the readings taken using an instrument may be more and some of the readings may be lesser than the actual value of the physical quantity.

The table below shows the results of a survey of 250 people who were asked whether they like to read and whether they play a musical instrument. According the the results, what is the probability that a randomly selected person who was surveyed likes to read, given that the person plays a musical instrument?

There are n students in a class. If, among those students, p% play at least 1 musical instrument, which of the following general expressions represents the number of students who play No musical instrument?

Why we use air columns in musical instruments ?

The length of string of a musical instrument is 90 cm and has fundamental frequency of 120 Hz where should it be pressed to produce fundamental frequency of 180 Hz

A musician recognizes the musical instrument by hearing the sound produced by it, even without seeing the instrument. Which characteristic of sound makes this possible ?

If the same note is being played on two different musical instruments, our ears can distinguish between the two sounds.

A string in a musical instrument is 50 cm long and its fundamental frequency is 800 Hz. If a frequency of 1000 Hz is to be produced, then required length of string is