If we study the vibration of a pipe open at both ends, then the following statements is not true

• Open end will be anti-node

• Odd harmonics of the fundamental frequency will be generated

• All harmonics of the fundamental frequency will be generated

• Pressure change will be maximum at both ends

A source of unknown frequency gives 4 beats/s when sounded with a source of known frequency 250 Hz. The second harmonic of the source of unknown frequency gives five beats per second when sounded with a source of frequency 513 Hz. The unknown frequency is

• 254 Hz

• 246 Hz

• 240 Hz

• 260 Hz

A whistle whose air column is open at both ends has a fundamental frequency of 5100 Hz. If the speed of sound in air is 340 ms^-1, the length of the whistle, in cm, is

• 5/3

• 10/3

• 5

• 20/3

A car is moving with a speed of 72 km-h^-1 towards a roadside source that emits sound at a frequency of 850 Hz. The car driver listens to the sound while approaching the source and again while moving away from the source after crossing it. If the velocity ofsound is 340 ms^-1, the difference of the two frequencies, the driver hears is

• 50 Hz

• 85 Hz

• 100 Hz

• 150 Hz

Sound waves are passing through two routes-one in straight path and the other along a semicircular path of radius r and are again combined into one pipe and superposed as shown in the figure. If the velocity of sound waves in the pipe is v, then frequencies of resultant waves of maximum amplitude will be integral multiples of

• $\frac{\mathrm{v}}{\mathrm{r} (\mathrm{\pi } - 2)}$

• $\frac{\mathrm{v}}{\mathrm{r} \left(\mathrm{\pi } - 1\right)}$

• $\frac{2\mathrm{v}}{\mathrm{r} \left(\mathrm{\pi } - 1\right)}$

• $\frac{\mathrm{v}}{\mathrm{r} \left(\mathrm{\pi } + 1\right)}$

286.

A train is moving with a uniform speed of 33 m/s and an observer is approaching the train with the same speed. If the train blows a whistle of frequency 1000 Hz and the velocity of sound is 333 m/s, then the apparent frequency of the sound that the observer hears is 

• 1220 Hz

• 1099 Hz

• 1110 hz

• 1200 Hz

The length of an open organ pipe is twice the length of another closed organ pipe. The fundamental frequency of the open pipe is 100 Hz. The frequency of the third harmonic of the closed pipe is

• 100 Hz

• 200 Hz

• 300 Hz

• 150 Hz