Two forks A and B when sounded together produce four beats s -1. The fork A is in unison with 30 cm length of a sonometer wire and B is in unison with 25 cm length of the same wire at the same tension. The frequencies of the forks are

Question

Two forks A and B when sounded together produce four beats s -1. The fork A is in unison with 30 cm length of a sonometer wire and B is in unison with 25 cm length of the same wire at the same tension. The frequencies of the forks are (A) 24 Hz , 28 Hz (B) 20 Hz , 24 Hz (C) 16 Hz , 20 Hz (D) 26 Hz , 30 Hz

Tardigrade Admin · Accepted Answer

(n1/n2)=(l2/l1)=(25/30) =(5/6) and n2-n1=4 On solving, we get n2=24 Hz n1=20 Hz

Q. Two forks $A$ and $B$ when sounded together produce four beats $s^{- 1}$ . The fork $A$ is in unison with $30 c m$ length of a sonometer wire and $B$ is in unison with $25 c m$ length of the same wire at the same tension. The frequencies of the forks are

24 Hz , 28 Hz

20 Hz , 24 Hz

16 Hz , 20 Hz

26 Hz , 30 Hz

$\frac{n _{1}}{n _{2}} = \frac{l _{2}}{l _{1}} = \frac{25}{30}$
$= \frac{5}{6}$
and $n_{2} - n_{1} = 4$
On solving, we get $n_{2} = 24 Hz$
$n_{1} = 20 Hz$

Q. Two forks A and B when sounded together produce four beats s−1. The fork A is in unison with 30cm length of a sonometer wire and B is in unison with 25cm length of the same wire at the same tension. The frequencies of the forks are