An air column of length is closed at one end and open at the other

PHYSICS · Single correct · A Level · Physics · Waves · Waves

Problem

An air column of length

L

is closed at one end and open at the other. Successive resonances are observed at frequencies

f

and

f+\Delta f

. Which expression correctly gives the speed of sound

v

in the tube in terms of

\Delta f

and

L

? (a)

4L\,\Delta f

(b)

L\,\Delta f

(c)

2L\,\Delta f

(d)

\dfrac{L\,\Delta f}{2}