## Question

### Solution

Correct option is

3.4 mm and 1.45 cm

Frequency of sound (V) = 100 kHz = 105 Hz

Speed of sound in air

Speed of sound in water

Since the reflected wave travels in air, its wavelength is

Since the transmitted wave travels in water, its wavelengths is

#### SIMILAR QUESTIONS

Q1

A stone hangs from the free end of a sonometer wire whose vibrating length, when tuned to a tuning fork, is 40 cm. When the stone hangs wholly immersed in water, the resonant length is reduced to 30 cm. The relative density of the stone is

Q2

A cylindrical tube, open at both ends, has fundamental frequency n. If one of the ends is closed, the fundamental frequency will become

Q3

Two loudspeakers A and B, 1.0 m apart, produce sound waves of the same wavelength and in the same phase. A sensitive sound detector, moving along PQ, parallel to line AB, 2.4 m away, detects maximum sound at P (on the perpendicular bisector of AB) another maximum sound when it first reaches Q directly opposite to B, as shown in fig. What is the wavelength of sound emitted by the speakers?

Q4

A progressive wave in a medium is represented by the equation

Where y and x are in cm and t in seconds. The maximum speed of a particle of the medium due to the wave is

Q5

A tuning fork of frequency 340 Hz is sounded above a cylindrical tube 1 m high. Water is slowly poured into the tube. If the speed of sound is 340 ms–1, at what levels of water in the tube will the sound of the fork be appreciably intensified?

Q6

A sonometer wire, 65 cm long, is in resonance with a tuning fork of frequency N. If the length of the wire is decreased by 1 cm and it is vibrated with the same tuning fork, 8 beats are heard per second. What is the value of N?

Q7

Two organ pipes, each closed at one end, give 5 beats per second when emitting their fundamental notes. If their lengths are in the ratio of 50 : 51, their fundamental frequencies (in Hz) are

Q8

Two sources A and B are sounding notes of frequency 680 Hz. A listener moves from A to B with a constant velocity u. If the speed of sound is 340 ms –1, what must be the value of u so that he hears 10 beats per second?

Q9

A hospital uses an ultrasonic scanner of frequency 3.2 MHz to locate tumours in a tissue. What is the wavelength of ultrasonic waves in a tissue in which the speed of the waves is 1.6 km s–1

Q10

The particle displacements in a travelling harmonic wave are given by

Where x and y are in centimeters and t is in seconds. What is the phase difference between oscillatory motion at two points separated by a distance of 4 m?