Question

The harmonics which are present in a pipe open at one end are:

• A. Odd harmonics
• B. Even harmonics
• C. Even as well as Odd harmonics
• D. None of the above

Answer 1

The correct option is A Odd harmonics

In a closed organ pipe (closed at one end) , the frequency of note in nth normal mode of vibration is given by ,

${\nu }_n=(2n-1){\nu }_1$ , $n=1,2,\mathrm{3.....}$ ,

it is $(2n-1)th$ harmonic .

hence , for $n=1$ , ${\nu }_1={\nu }_1$ , (first harmonic)

for $n=2$ , ${\nu }_2=3{\nu }_1$ , (third harmonic)

for $n=3$ , ${\nu }_3=5{\nu }_1$ , (fifth harmonic)

we can see that only odd harmonics are produced in a closed pipe .