For a finite control of volume between two sections, section 1 and section 2, momentum principle is P₁A₁ + P₂A₂ + F = mV₂mV₁. Where F = component of resultant force exerted on fluid walls.

Compressible flow is a branch of fluid mechanics that deals with different types of flow. Its main significance lies on change in fluid density. It deals with gas dynamics. Flow is assumed to be isentropic.

The sum of enthalpy and kinetic energy remains a constant in adiabatic flow. It performs a similar role that internal energy performs during a nonflowing system. Thus, correct option is Adiabatic flow.

The related assumption of a compressible fluid flow is No-slip condition. It is assumed that flow velocity at solid surface is equal to velocity of surface itself. It is in direct consequence with continuum flow.

Mass flow rate is given by Q = m/p. This is a relation expressed for mass flow rate. With presence of a converging duct, velocity increases. At this point, area of duct is less than zero.

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

Pressure is inversely proportional to velocity. So, with increase in pressure, exit velocity decreases. We know that pressure is equal to force per unit area, this contradicts above statement.

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

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

Compressible flow is a branch of fluid mechanics that deals with different types of flow. Its main significance lies in change in fluid density. It deals with gas dynamics.