Question

) An air column of length 32 cm of a resonance tube is in unison with tuning fork. If the length is changed to 32.4 cm, 5 beats per second are heard. Find the frequency of the tuning fork. (Ans: n2 = 400 Hz)​

Answer 1

Answer:

256hz

Explanation:

264 Hz,256 Hz

Since v=nλ and velocity in two cases must be same as the medium is same. λ

1

=4(32) cm=128 cm and λ

2

=2(66) cm=132 cm.

Hence,

n

2

n

1

=

λ

1

λ

2

=

128

132

=

32

33

.

Also, n

1

−n

2

=8,

Solving these gives n

1

=264Hz and n

1

=256Hz.