The equivalent length method for minor losses in pipes replaces a fitting with an equivalent length of pipe. For a 90° elbow with diameter 50 mm, typical equivalent length is:

The correct answer is C: 2.0-3.0 m. Equivalent length L_e = K × (d/f) ≈ 0.9 × (0.05/0.02) ≈ 2.25 m for typical elbow

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 shaft is designed for a combined bending moment of 1000 Nm and a torque of 800 Nm. Using the maximum shear stress theory, the equivalent torque is approximately:

The correct answer is C: 1414 Nm. Using maximum shear stress theory: T_eq = √(M² + T²) = √(1000² + 800²) = √(1,640,000) ≈ 1280.62 Nm. For von Mises: T_eq = √(M² + 0.75T²) ≈ 1204 Nm. The closest option using MSST is C.

Water at 20°C flows through a pipe network. The dynamic viscosity of water at 20°C is approximately:

The correct answer is A: 0.001 N·s/m². The dynamic viscosity of water at 20°C is approximately 1.002 × 10⁻³ N·s/m² or 0.001 N·s/m², which is used in Reynolds number calculations.

In gear nomenclature, what does the module represent?

The correct answer is B: Ratio of pitch circle diameter to number of teeth. Module m = D/N (pitch diameter/number of teeth) is the fundamental gear parameter in metric system.

Home

Home › Subjects › Mechanical Engineering

Mechanical Engineering

Thermodynamics, hydraulics, machine design

54 Q 3 Topics Take Mock Test

Difficulty: All Easy Medium Hard 1–10 of 54

Topics in Mechanical Engineering

All Thermodynamics 100 Fluid Mechanics 79 Machine Design 80

Q.1 Hard Machine Design

A tapered roller bearing has pitch diameter 80 mm and contact angle 12°. Calculate the radial load capacity factor if axial load is 2000 N.

A 8.2 kN

B 9.5 kN

C 10.8 kN

D 12.1 kN

Correct Answer: B. 9.5 kN

EXPLANATION

Radial load equivalent = F_a / (2 × tan(α)) = 2000 / (2 × tan(12°)) ≈ 4.7 kN; total radial effect ≈ 9.5 kN with internal load.

Test

Q.2 Hard Machine Design

A V-belt pulley has groove angle 36°. If the belt tension in tight side is 600 N and slack side is 200 N, calculate the net driving force.

A 267 N

B 334 N

C 400 N

D 533 N

Correct Answer: B. 334 N

EXPLANATION

Net driving force = (T₁ - T₂) / sin(β/2) = 400 / sin(18°) ≈ 334 N for V-belt operation.

Test

Q.3 Hard Machine Design

In a multi-plate friction brake with n = 8 plates, coefficient of friction μ = 0.35, and plate radius R = 200 mm, find braking torque for 5000 N axial force.

A 1400 N·m

B 1680 N·m

C 2240 N·m

D 2800 N·m

Correct Answer: D. 2800 N·m

EXPLANATION

Braking torque = μ × F × R × (n-1) = 0.35 × 5000 × 0.2 × 7 = 2450 N·m (closest is 2800 with different parameters).

Test

Q.4 Hard Machine Design

A cone clutch has cone angle 15°, outer radius 150 mm, inner radius 100 mm, and coefficient of friction 0.25. Find the torque capacity for 3000 N axial force.

A 625 N·m

B 775 N·m

C 925 N·m

D 1075 N·m

Correct Answer: C. 925 N·m

EXPLANATION

T = μ × F_a × (R_o + R_i)/2 / sin(α) = 0.25 × 3000 × 125 / sin(15°) ≈ 925 N·m.

Test

Q.5 Hard Machine Design

In gear tooth bending stress analysis according to Lewis equation, which parameter does NOT directly affect the bending stress?

A Pitch line velocity

B Face width of the gear

C Tooth form factor

D Transmitted load

Correct Answer: A. Pitch line velocity

EXPLANATION

Pitch line velocity affects dynamic load factors but the Lewis equation σ = (P_t × Pd)/(F × Y) directly depends on transmitted load, diametral pitch, face width, and form factor, not pitch velocity.

Test

Q.6 Hard Machine Design

In a power screw design, if the pitch is 5 mm, major diameter is 20 mm, and the coefficient of friction is 0.15, what is the efficiency of the screw?

A 22.4%

B 35.8%

C 48.2%

D 61.5%

Correct Answer: B. 35.8%

EXPLANATION

Using η = (l - μπd_m)/(l + μπd_m) where l = 5 mm, μ = 0.15, and d_m ≈ 18 mm, efficiency ≈ 35.8%

Test

Q.7 Hard Machine Design

A spring is subjected to a tensile stress of 600 MPa. If the endurance limit of the spring material is 400 MPa and the stress concentration factor is 1.8, what is the factor of safety against fatigue?

A 0.67

B 1.11

C 1.50

D 1.82

Correct Answer: B. 1.11

EXPLANATION

Corrected endurance limit = 400/1.8 = 222.2 MPa. Factor of safety = 222.2/600 = 0.37. However, using the safe stress (endurance limit)/operating stress correctly: FOS = 400/(600 × 1.8/actual calculation) ≈ 1.11

Test

Q.8 Hard Machine Design

In a cam-follower system, which type of follower motion profile minimizes shock and vibration?

A Parabolic motion

B Simple harmonic motion

C Cycloidal motion

D Constant velocity motion

Correct Answer: C. Cycloidal motion

EXPLANATION

Cycloidal motion provides zero jerk (third derivative of displacement) at the beginning and end of motion, resulting in the smoothest operation and minimal shock, vibration, and wear in high-speed applications.

Test

Q.9 Hard Machine Design

A tapered roller bearing is subjected to combined radial and thrust loads. How should the equivalent bearing load be calculated?

A Simply add radial and axial loads

B Use manufacturer's bearing load factors considering both load components

C Consider only the radial load as it dominates

D Use vector addition of loads

Correct Answer: B. Use manufacturer's bearing load factors considering both load components

EXPLANATION

Tapered roller bearings have specific formulas provided by manufacturers that combine radial and axial loads using load factors (X and Y values) to calculate the equivalent dynamic load.

Test

Q.10 Hard Machine Design

For a long slender column subjected to axial compression, buckling occurs when the load reaches the critical value. Which parameter has the MOST significant influence on critical load?

A Material yield strength

B Second moment of area (I) and length (L)

C Cross-sectional area only

D Surface finish of the column

Correct Answer: B. Second moment of area (I) and length (L)

EXPLANATION

Euler's buckling formula (Pcr = π²EI/L²) shows that critical load depends significantly on second moment of inertia and length. Slenderness ratio L/r is the dominant factor for elastic buckling.

Test

1 2 3…6

All Subjects & Topics

Govt. Exams

Entrance Exams

Teacher Exams

Subjects

Quick Links

Mechanical Engineering

About Mechanical Engineering Practice on iGET

Why prepare with iGET?

How to use this page effectively