Q. A tuning fork of frequency 250 Hz produces a beat frequency of 10 Hz when sounded with a sonometer vibrating at its fundamental frequency. When the tuning fork is filed, the beat frequency decreases. If the length of the sonometer wire is $0.5\ m,$ the speed of the transverse wave is
A) $260\ ms^{- 1}$
B) $250\ ms^{- 1}$
C) $240\ ms^{- 1}$
D) $500\ ms^{- 1}$
Explanation
(a) Frequency of sonometer wire will be $(250 + 10)$ or $(250 - 10)$ on filling for $k$ beat frequency decrease
$\therefore$ Frequency of sonometer wire $= 260\ Hz$
Now using $v = \frac{v}{2l}$
$v = 260 \times 2 \times 0.5$
$\Rightarrow v = 260\ m/s$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.