Question

A tube closed at one end and containing air produces, when excited the fundamental note of frequency 512 Hz. If the tube is open at both ends, the fundamental frequency that can be excited is (in Hz)

• A. 128
• B. 256
• C. 512
• D. 1024

Answer 1

Answer: (D)

1024

The fundamental frequency for a tube closed at one end is

${\nu }_c=\frac{v}{4l}$

where variables have their usual meanings

$512\times 4=\frac{v}{l}$ ...................(1) ................(given)

Now, The fundamental frequency for a tube closed at one end is

${\nu }_o=\frac{v}{2l}$

where variables have their usual meanings

${\nu }_o=\frac{1}{2}512\times 4$ .........................from(1)

${\nu }_o=1024Hz$