List of top Mechanical Engineering Questions

When a ball mill rotates at a speed higher than the critical speed, what happens to its efficiency?
Which mechanical drive is specifically used to impart a reciprocating or oscillatory motion to another body in contact?
What is the stress developed when a steel rod of radius \(10 \, \text{mm}\) is stretched by a \(100 \, \text{kN}\) force?
A ball is thrown vertically upward with a velocity of \(5 \, \text{m/s}\); if it takes 10 sec for the upward journey, how long does the downward journey take?
Which translatory joint in a robot configuration is known as a sliding joint?
What is the natural frequency of a free vibration system defined by the equation \( \ddot{X} + 36\pi^2 X = 0 \)?
The polar section modulus for a circular shaft of diameter \(d\) is given by which formula?
For a DC power source for arc welding with characteristics \(3V + I = 240\), what voltage \(V\) yields maximum power?
Forces whose line of action passes through a common point are known as what?
Which of the following is a coarse crusher used in mechanical operations?
In a psychrometric chart, what does a vertical downward line represent?
Gas contained in a closed system consisting of a piston-cylinder arrangement is expanded. Work done by the gas during expansion is 50 kJ. The decrease in internal energy of the gas during expansion is 30 kJ. The heat transfer during the process is equal to:
The Nusselt number is related to the Reynolds number in laminar and turbulent flows respectively as:
The following conditions must be satisfied for a perfect truss (m = number of members, j = number of joints):
Match List-I with List-II
List-I (Details of the processes of the cycle)List-II (Name of the cycle)
(A) Two adiabatic, one isobaric and two isochoric(I) Diesel
(B) Two adiabatic and two isochoric(II) Carnot
(C) Two adiabatic, one isobaric and one isochoric(III) Dual
(D) Two adiabatics and two isothermals(IV) Otto
Choose the correct answer from the options given below:
Using the method of Regula Falsi, a root of the equation \( x^3 + x^2 - 3x - 3 = 0 \) lying between 1 and 2 is
Match List-I with List-II
List-I
(Dimensionless Numbers)		List-II
(Relationship)
(A) Froude's Number(II) \( \sqrt{\frac{\text{Inertia force}}{\text{Gravity force}}} \)
(B) Mach's Number(IV) \( \sqrt{\frac{\text{Inertia force}}{\text{Elastic Force}}} \)
(C) Euler's Number(I) \( \frac{\text{Pressure Force}}{\text{Inertia Force}} \)
(D) Weber's Number(III) \( \frac{\text{Inertia Force}}{\text{Surface Tension Force}} \)
Choose the correct answer from the options given below:
An aeroplane is flying at a height of 15 km, where the temperature is -50°C. Assuming \( k = 1.4 \) and \( R = 287 \, \text{J/K . kg} \), the approximate speed of the plane corresponding to \( M = 2.0 \) will be?
The thickness of a laminar boundary layer at a distance \( x \) from the leading edge over a flat plate varies as
For an insulated tip, the fin efficiency is given by
The latent heat of vaporization at the critical point is
The polar section modulus for a circular shaft of diameter "d" is:
A Newtonian fluid is defined as the fluid which
Bernoulli's theorem deals with the law of conservation of
Which thermodynamics law predicts correctly the degree of completion of a chemical reaction?