Engineering Questions with Answers - Multiple Choice Questions

MCQs on Velocity of Sound or Pressure Wave in a Fluid – 2

1 - Question

A wave that has propagating disturbance is called ________
a) Shock wave
b) Compression wave
c) Compressed wave
d) Longitudinal wave

a
Explanation: Shock wave is defined as the wave that has a propagating disturbance. When the propagating wave move faster than the local speed of fluid, it is called as a shock wave. It can propagate through any medium.

2 - Question

A shock wave carries _______
a) Heat
b) Pressure
c) Energy
d) Temperature

c
Explanation: The shock wave carries energy and can propagate through a medium. It can be characterized as abrupt. It is due to the discontinuous changes in pressure, density and temperature of the medium.

3 - Question

Shock waves can be normal, oblique and bow.
a) True
b) False

a
Explanation: Shock waves can be at normal angles, oblique angles and bow angles. Normal angle is perpendicular to the shock medium’s flow direction. Oblique angle is at the direction of flow. Bow occurs at the front of the object.

4 - Question

Bow occurs at what Mach number?
a) Mach number = 0
b) Mach number is negative
c) Mach number = 1
d) Mach number greater than 1

d
Explanation: Bow occurs when the Mach number is greater than one. It occurs at the upstream of the front of a blunt object. It happens when the velocity exceeds Mach 1.

5 - Question

A boundary over which physical conditions undergo changes is called _______
a) Shear front
b) Shock front
c) Contact front
d) Cap front

b
Explanation: Shock front is defined as the boundary over which the physical conditions of a fluid undergo abrupt changes. This happens due to the shock wave. Thus, the correct choice is option Shock front.

6 - Question

A shock wave caused by driver gas is called _______
a) Shear front
b) Shock front
c) Contact front
d) Cap front

c
Explanation: Contact front is defined as a shock wave caused by a driver gas. It is the boundary layer between the driver gases and the driven gases. The main function of the contact front is to trails the shock front.

7 - Question

When the fluid flow is discontinuous, what is established?
a) Heat
b) Pressure
c) Control volume
d) Temperature

c
Explanation: When the fluid flow is discontinuous, a control volume is established. It is established around the shock wave. It is treated as a discontinuity where the entropy increases to over a infinitesimally large region.

8 - Question

Shock waves that deviate from the arbitrary angle are called_______
a) Oblique shock
b) Bow shock
c) Normal shock
d) Detonation

a
Explanation: Shock waves in a flow field which are attached to a body start deviating at some arbitrary angle from the flow direction of the fluid. This shock so developed due to angle deviation is called as oblique shock.

9 - Question

When a shock wave forms continuous pattern, it is called ________
a) Oblique shock
b) Bow shock
c) Normal shock
d) Detonation

b
Explanation: Bow occurs when the Mach number is greater than one. It occurs at the upstream of the front of a blunt object. It happens when the velocity exceeds Mach 1. When a shock wave forms continuous pattern, it is called a bow shock.

10 - Question

Shocks generated due to an interaction of two bodies are called ______
a) Oblique shock
b) Bow shock
c) Moving shock
d) Detonation

c
Explanation: Shocks that are generated by the interaction of two bodies of gas. This interaction takes place at different pressure, with the shock wave propagating into a lower pressure gas and an expansion wave propagates into a high-pressure gas

11 - Question

Shocks generated due to trailing exothermic reaction is called ______
a) Oblique shock
b) Bow shock
c) Moving shock
d) Detonation