In brake design, which factor is MOST critical when designing brakes for automotive applications operating at high temperatures?

The correct answer is A: Thermal conductivity and heat dissipation capacity. High-temperature brake operation requires materials with excellent thermal conductivity to dissipate heat quickly, preventing brake fade and maintaining friction coefficient stability.

In spring design, what is the primary effect of shot peening on the fatigue strength of a spring?

The correct answer is B: Induces residual compressive stresses that improve fatigue strength. Shot peening creates compressive residual stresses at the surface, which significantly improve fatigue strength by preventing crack initiation and propagation from the surface.

In gear design, what does the term 'Module' represent?

The correct answer is A: Ratio of pitch diameter to number of teeth. Module is defined as the ratio of pitch circle diameter to the number of teeth (m = D/N). It determines the size of the gear teeth.

Which of the following has the highest specific heat capacity among common substances at room temperature?

The correct answer is A: Water. Water has exceptionally high specific heat (~4.18 kJ/kg·K), much higher than metals (iron ~0.46) and air (~1.01). This is due to hydrogen bonding in water.

A reversible adiabatic process for an ideal gas is also known as:

The correct answer is C: Isentropic process. A reversible adiabatic process has constant entropy (dS = 0), making it isentropic. This is a key assumption in many thermodynamic analysis for ideal processes.

Home

Home › Subjects › Mechanical Engineering › Fluid Mechanics

Mechanical Engineering
Fluid Mechanics

Thermodynamics, hydraulics, machine design

37 Q 3 Topics Take Mock Test

Difficulty: All Easy Medium Hard 21–30 of 37

Topics in Mechanical Engineering

All Thermodynamics 100 Fluid Mechanics 79 Machine Design 80

Q.21 Medium Fluid Mechanics

A pipeline carrying oil (ν = 2 × 10⁻⁴ m²/s) has diameter 0.5 m and velocity 2 m/s. The flow regime is:

A Laminar (Re < 2300)

B Transitional (2300 < Re < 4000)

C Turbulent (Re > 4000)

D Cannot be determined

Correct Answer: C. Turbulent (Re > 4000)

EXPLANATION

Re = vd/ν = (2 × 0.5)/(2 × 10⁻⁴) = 5000 > 4000, so turbulent

Test

Q.22 Medium Fluid Mechanics

The Froude number characterizes the relative importance of:

A Inertial forces to viscous forces

B Inertial forces to gravitational forces

C Surface tension to inertial forces

D Pressure forces to elastic forces

Correct Answer: B. Inertial forces to gravitational forces

EXPLANATION

Fr = v/√(gL) compares inertial forces (ρv²) with gravitational forces (ρgL).

Test

Q.23 Medium Fluid Mechanics

A convergent-divergent nozzle (De Laval nozzle) accelerates gas to supersonic speeds. The throat area compared to exit area is:

A Always larger

B Always smaller

C Always equal

D Depends on inlet conditions

Correct Answer: B. Always smaller

EXPLANATION

In a convergent-divergent nozzle, throat area is smallest and exit area is larger for supersonic flow.

Test

Q.24 Medium Fluid Mechanics

For a turbulent flow in pipes, the friction factor f in the Darcy-Weisbach equation depends primarily on:

A Velocity and pipe diameter only

B Reynolds number and relative roughness

C Temperature and pressure only

D Fluid density only

Correct Answer: B. Reynolds number and relative roughness

EXPLANATION

Friction factor for turbulent flow depends on Re and roughness (ε/d) as shown in Moody diagram.

Test

Q.25 Medium Fluid Mechanics

In a U-tube manometer with mercury, if one leg shows 50 mm height difference, the pressure difference is:

A 0.05 × ρ_mercury × g Pa

B 50 × ρ_mercury × g Pa

C 0.05 × ρ_water × g Pa

D Cannot be determined without knowing fluid type

Correct Answer: B. 50 × ρ_mercury × g Pa

EXPLANATION

ΔP = ρgh = ρ_mercury × 9.81 × 0.05 ≈ 50 × ρ_mercury × g Pa (approximately)

Test

Q.26 Medium Fluid Mechanics

A jet of water impinges on a flat plate perpendicular to its surface. If jet velocity is 10 m/s and jet area is 0.01 m², the force on the plate is approximately:

A 100 N

B 500 N

C 1000 N

D 2000 N

Correct Answer: C. 1000 N

EXPLANATION

Force F = ρAv² = 1000 × 0.01 × 10² = 1000 N (using ρ = 1000 kg/m³ for water)

Test

Q.27 Medium Fluid Mechanics

In a pitot tube, the stagnation pressure and static pressure are measured. The velocity at the measurement point is:

A v = √(2(P_stagnation - P_static)/ρ)

B v = (P_stagnation - P_static)/(2ρ)

C v = (P_stagnation + P_static)/ρ

D v = P_stagnation/(ρ × P_static)

Correct Answer: A. v = √(2(P_stagnation - P_static)/ρ)

EXPLANATION

From Bernoulli's equation applied between static and stagnation points: v = √(2ΔP/ρ)

Test

Q.28 Medium Fluid Mechanics

The major loss in pipe flow (Darcy-Weisbach equation: hf = f(L/D)(V²/2g)) is primarily due to:

A Sudden expansion or contraction

B Bends and elbows in pipes

C Friction between fluid and pipe wall

D Elevation changes

Correct Answer: C. Friction between fluid and pipe wall

EXPLANATION

Major losses or friction losses occur due to wall shear stress and account for the majority of energy dissipation in long straight pipe sections. This is captured by the Darcy friction factor.

Test

Q.29 Medium Fluid Mechanics

A venturi meter is used to measure fluid flow rate. The principle it operates on is:

A Archimedes principle

B Continuity equation and Bernoulli's equation

C Stokes law

D Newton's second law of motion

Correct Answer: B. Continuity equation and Bernoulli's equation

EXPLANATION

Venturi meter uses both continuity equation (conservation of mass) and Bernoulli's equation (energy conservation) to relate pressure difference to flow velocity.

Test

Q.30 Medium Fluid Mechanics

Which of the following is a dimensionless number used in fluid mechanics that compares inertial forces to surface tension forces?

A Weber number

B Froude number

C Strouhal number

D Grashof number

Correct Answer: A. Weber number

EXPLANATION

Weber number We = ρV²D/σ represents the ratio of inertial to surface tension forces. It's important in two-phase flows and atomization studies.

Test

1 2 3 4

All Subjects & Topics

Govt. Exams

Entrance Exams

Teacher Exams

Subjects

Quick Links

Mechanical Engineering Fluid Mechanics

Mechanical Engineering
Fluid Mechanics