NEET Physics Basic of Mechanical Waves Progressive and Stationary Waves MCQs Set 01

Question. The reason for introducing Laplace correction in the expression for the velocity of sound in a gaseous medium is
(a) no change in the heat of the medium during the propagation of the sound through it
(b) change in the pressure of the gas due to the compression and rarefaction
(c) change in the volume of the gas
(d) no change in the temperature of the medium during the propagation of the sound through it

Answer: A

Question. Which of the following changes at an antinode in a stationary wave?
(a) Neither pressure nor density
(b) Both pressure and density
(c) Pressure only
(d) Density only

Answer: A

Question. What is the effect of humidity on sound waves when humidity increases?
(a) Speed of sound waves is more
(b) Speed of sound waves is less
(c) Speed of sound waves remains same
(d) Speed of sound waves becomes zero

Answer: A

Question.  Which of the following statements is/are correct about the standing wave?
I. In a standing wave the disturbance produce is confined
to the region where it is produced.
II. In a standing wave, all the particles cross their mean position together.
III. In a standing wave, energy is transmitted from one region of space to other.
(a) I and II
(b) Only III
(c) Only II
(d) I, II and III

Answer: A

Question. Assertion : Solids can support both longitudinal and transverse waves but only longitudinal waves can propagate in gases.
Reason : For the propagation of transverse waves, medium must also necessarily have the property of rigidity
(a) Assertion is correct, reason is correct; reason is a correct explanation for assertion
(b) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(c) Assertion is correct, reason is incorrect
(d) Assertion is incorrect, reason is correct

Answer: A

Question. The bulk modulus of a liquid of density 8000 kg m^–3 is 2 × 109 N m–2. The speed of sound in that liquid is (in m s–1)
(a) 500
(b) 100
(c) 250
(d) 200

Answer: A

Question. The rate of transfer of energy in a wave depends
(a) directly on the square of the wave amplitude and square of the wave frequency
(b) directly on the square of the wave amplitude and root of the wave frequency
(c) directly on the wave amplitude and square of the wave frequency
(d) None of these

Answer: A

Question. The velocity of sound in hydrogen is 1224 m/s. Its velocity in a mixture of hydrogen and oxygen containing 4 parts by volume of hydrogen and 1 part oxygen is
(a) 612 m/s
(b) 2448 m/s
(c) 306 m/s
(d) 1224 m/s

Answer: A

Question. A hospital uses an ultrasonic scanner to locate tumours in a tissue. The operating frequency of the scanner is 4.2 MHz. The speed of sound in a tissue is 1.7 km/s. The wavelength of sound in tissue is close to
(a) 4 × 10^–4 m
(b) 4 × 10^–3 m
(c) 8 × 10^–4 m
(d) 8 × 10^–3 m

Answer: A

Question. When a sound wave goes from one medium to another, the quantity that remains unchanged is
(a) frequency
(b) amplitude
(c) wavelength
(d) speed

Answer: A

Question. For which of the following do the longitudinal waves exist?
(a) Both
(b) Air
(c) Water
(d) None of these

Answer: A

Question. Sound travels in rocks in the form of
(a) both longitudinal and transverse elastic waves
(b) non-elastic waves
(c) transverse elastic waves only
(d) longitudinal elastic waves only

Answer: A

Question. From a point source, if amplitude of waves at a distance r is A, its amplitude at a distance 2r will be
(a) A/2
(b) A/4
(c) 2 A
(d) A

Answer: A

Question. The property of a medium necessary for wave propagation is
(a) All of the above
(b) elasticity
(c) inertia
(d) low resistance

Answer: A

Question. The ratio of the speed of a body to the speed of sound is called
(a) Mach number
(b) sonic index
(c) Doppler ratio
(d) refractive index

Answer: A