Get Answers to all your Questions

header-bg qa

 A bat emits the ultrasonic. Sound of frequency 2000 KHZ  in air.
If the sound meets a water surface, what is the wavelength of
(a) The reflected sound,
(b) The transmitted sound
speed of sound in air is 332 m/s and in Water 1400 m/s
 

Option: 1

\lambda=7 \times 10^{-4} \mathrm{~m},\lambda=166\times10^{-6}


Option: 2

\lambda=6 \times 10^{-4} \mathrm{~m},\lambda=167\times10^{-6}


Option: 3

\lambda=8 \times 10^{-4} \mathrm{~m},\lambda=169\times10^{-6}


Option: 4

\lambda=4 \times 10^{-4} \mathrm{~m},\lambda=165\times10^{-6}


Answers (1)

best_answer

\text { Here } V=2000 \mathrm\,{KHz}=2000 \times 10^3 \mathrm{~Hz} \\

=2 \times 10^6 \mathrm{~Hz}

velocity of sound in air,  U_a=332 \mathrm{~m} / \mathrm{s} 

the velocity of sound in water  U_W=1400 \mathrm{~m} / \mathrm{s}

(a) For reflected sound; medium remains the same

\therefore \text { Wavelength } \lambda=\frac{ { U_{a} }}{V}=\frac{332}{2 \times 10^6} \\

=166 \times 10^{-6} \mathrm{~m}

(b) For the sound transmitted in to Water wavelength 

\lambda =\frac{U _{W}}{V}=\frac{1400}{2 \times 10^6}

700 \times 10^{-6}=7 \times 10^{-4} \mathrm{~m}

Posted by

Suraj Bhandari

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE