Engineering Questions with Answers - Multiple Choice Questions

# MCQs on Velocity of Sound or Pressure Wave in a Fluid – 1

1 - Question

Speed is of sound is the _________
a) Distance travelled per unit length
b) Distance travelled per unit time
c) Distance travelled per unit pressure
d) Distance travelled per unit temperature

b
Explanation: The speed of sound is defined as the distance travelled per unit time. It is due to the sound wave. The sound wave propagates through the medium.

2 - Question

The sound wave is transmitted through liquids as_________
a) Longitudinal waves
b) Transverse waves
c) Elongated waves
d) Refracted waves

a
Explanation: The sound wave is transmitted through liquids, gases and plasma as longitudinal waves. It is also called as compressed waves. Longitudinal waves require a medium to propagate. Thus, the correct answer is Longitudinal waves.

3 - Question

What are the assumptions made for a fluid flow through a pipe?
a) Fluid inertia is not taken
b) Viscosity is not taken
c) Volume is not considered
d) Mass is not considered

a
Explanation: During a fluid flow through a pipe, there are various design considerations. But, the two major assumptions are that the flow is assumed to be fully developed. Also, fluid inertia is not taken into account

4 - Question

Which among the following is not generic property of sound?
a) Viscosity
b) Amplitude
c) Direction
d) Frequency

a
Explanation: Viscosity is not a generic property sound. It is defined as the property of resistance to flow of fluid. Resistance to flow of fluid takes place when one layer of fluid slides over the other. Viscosity is not a generic property.

5 - Question

Sound perceptible by humans has frequencies from _______
a) 20 to 2000 Hz
b) 20 to 20000 Hz
c) 10 to 10000 Hz
d) 30 to 30000 Hz

b
Explanation: Sounds that are audible to a human ear ranges from 20 to 20000 Hz. At standard temperature and pressure of air, the corresponding wavelengths of sound range from 17m to 17mm.

6 - Question

What is the speed of sound in dry air?
a) 331.2 m/s
b) 300 m/s
c) 250 m/s
d) 230 m/s

a
Explanation: The speed of sound in dry air at a temperature of zero degrees Celsius is equal to 331.2 m/s. Speed of sound in air is denoted by the symbol ‘c’. Thus the correct answer for the following is 331.2 m/s.

7 - Question

What is the speed of sound at 20oC?
a) 331.2 m/s
b) 350 m/s
c) 343 m/s
d) 300 m/s

c
Explanation: The speed of sound in dry air at a temperature of 20oC is equal to 343 m/s. It is found out using the relation of kilometre and miles. One kilometre = 2.91 seconds, and one mile = 4.69 seconds.

8 - Question

Speed of sound in an ideal gas depends on _______
a) Temperature and pressure
b) Surface area and volume
c) Temperature and composition
d) Composition and surface area

c
Explanation: Speed of sound in ideal gas depends on its composition and temperature. The speed of sound has a weak dependence on frequency and pressure. As there is a slight deviating behaviour in an ideal fluid.

9 - Question

Transverse wave is also called as ________
a) Shear wave
b) Compression wave
c) Compressed wave
d) Longitudinal wave

a
Explanation: Transverse wave is also called as a shear wave. Transverse wave or shear waves occur only in solids. It occurs only in solids because only solids support elastic deformations. It is also called as an elastic wave.

10 - Question

Which among the following determines the geometric orientation of transverse waves?
a) Dichroism
b) Optical activity
c) Polarization
d) Photon spin