Related InterviewSolutions

• Calculate the interval between two sound waves of frequencies 1000 Hz and 400 Hz. Express the interval on logarithmic scale and in centioctaves. [Hint absolute interval `= n_(1)//n_(2)` interval on log scale log `n_(1)//n_(2)`, interval in centioctaves `= (log n_(1)//n_(2))/(log 2) xx 100.`]
• `S_(1)` and `S_(2)` are two loudspeakers with the same frequency of 165 Hz and acoustic output `1.2 xx 10^(-3)` and `1.8 xx 10^(-3)` watt respectively. They vibrate in the same phase. P is a point at a distance 4 m from `S_(1)` and 3 m from `S_(2)`. (a) How are the phases of the two waves arriving at P related ? (b) What is the intensity of P if `S_(1)` is turned off `(S_(2) " on")`? (c) What is the intensity of sound at P if `S_(2)` is turmed off ? (d) What is the intensity at P with `S_(1)` and `S_(2)` on ? [Hint : For phase relationship see example 6 of chapter 1. Intensity is inversely proportional to square of the distance]
• A smoked plate falls vertically under gravity. A tuning fork traces wave on it. It is found that the lengths of two conscutive grounps of 10 waves are 5.143 and 6.64 cm respectively. What is the frequecny of the fork ?
• Calculate the amplitude of vibrations of air particles when a wavee of intensity `10^(-3) "watt"//m^(2)` is produced by a tuning fork of frequency 540 Hz. Velocity of sound in air `= 340 m s^(-1)` and density of air `= 1.3 kg m^(-3)`
• A note of frequency 300 Hz has an intensity of 1 microwatt per square metre. What is the amplitude of the air vibrations caused by this sound ? (Density of air `= 1.293 kg m^(-3)` and velocity of sound in air `= 332 ms^(-1)`)
• A siren wth a ring of 200 holes is making 132 revolutions per mintue and is found to emit a note which is an octave higher than of a tuning fork. Find the frequency of the latter.
• A siren with 20 holes in its disc given 5 beats per second with a closed pipe sounding its fundamental note when the disc makes 2400 revolution per minute. What is the effective length of the pipe? (velocity of sound in air `= 360 ms^(-1)`)