# Recent questions and answers in Mechanical Engineering

If a shaft made of ductile material is subjected to combined bending and twisting moments, calculation based on which one of the following theories would give the most conservative values ? (A) Maximum principle stress theory (B) Maximum shear stress theory (C) Maximum strain energy theory (D) Maximum distortion energy theory

Two metallic blocks having masses in the ratio 2:3 are made to slide down a frictionless inclined plane starting from rest position. When the blocks reach the bottom of the inclined plane, they will have their kinetic energies in the ratio : (A) 2:3 (B) 3:5 (C) 3:2 (D) 7:4

The train value of a gear train is : (A) equal to velocity ratio (B) reciprocal of velocity ratio (C) always greater than unity (D) none of the above

In a clock mechanism, the gear train used to connect minute hand to hour hand, is : (A) Epicyclic gear train (B) Reverted gear train (C) Compound gear train (D) Simple gear train

If the rotating mass of a rim type flywheel is distributed on another rim type flywheel whose mean radius is half the mean radius of the former, then the energy stored in the latter at the same speed will be : (A) Four times the first one (B) Same at the first one (C) One fourth of the first one (D) One and half times the first one

Material having highest cutting speed is : (A) Cast iron (B) Bronze (C) Aluminium (D) High carbon steel

Angle between the shear plane and work surface is known as : (A) lip angle (B) rake angle (C) cutting angle (D) shear angle

Binding material used in cemented carbide tools is : (A) Nickel (B) Cobalt (C) Chromium (D) Silicon

The usual ratio of forward and return stroke in shaper is : (A) 2:1 (B) 1:2 (C) 2:3 (D) 3:2

Tool life is most affected by : (A) cutting speed (B) tool geometry (C) feed and depth (D) microstructure of material being cut

The main object of scientific layout is : (A) to produce better quality of product (B) to utilise maximum floor area (C) to minimise production delays (D) all of these

In value engineering, the term value refers to : (A) manufacturing cost of the product (B) selling price of the product (C) total cost of the product (D) utility of the product

In axial flow fans and turbines, fluid enters and leaves as follows : (A) radially, axially (B) axially, radially (C) axially, axially (D) radially, radially

Which of the following instrument can be used for measuring speed of an aeroplane ? (A) orifice plate (B) hot wire anemometer (C) rotameter (D) pitot tube

A twist drill is a : (A) side cutting tool (B) front cutting tool (C) end cutting tool (D) none of these

In inventory control theory, the economic order quantity is : (A) average level of inventory (B) optimum lot size (C) capacity of a warehouse (D) lost size corresponding to break-even analysis

Power transmitted through a pipe is maximum when the loss of head due to friction is : (A) one-half of the total head supplied (B) one-third of the total head supplied (C) one-fourth of the total head supplied (D) zero

The efficiency of a centrifugal pump is maximum when its blades are : (A) straight (B) bent forward (C) bent backward (D) bent forward first and then backward

The comfort conditions in air conditioning are : (A) 22 ºC dry bulb temperature and 60% relative humidity (B) 25 ºC dry bulb temperature and 100% relative humidity (C) 20º C dry bulb temperature and 75% relative humidity (D) 15º C bulb temperature and 80% relative humidity

Air is normally dehumidified by : (A) injecting water (B) passing steam (C) heating (D) cooling

Dew point temperature is constant as long as there is : (A) no change in moisture content of the air (B) no change in volume of air (C) no change in dry bulb and wet bulb temperature (D) no change in relative and specific humidity of air

The most suitable refrigerant for a commercial ice plant is : (A) brine (B) NH3 (C) Freon (D) air

Gantt chart is used for : (A) inventory control (B) material handling (C) production schedule (D) machine repair schedules

The ratio of maximum displacement of the forced vibration to the deflection due to static force is known as : (A) Damping Factor (B) Damping Coefficient (C) Logarithmic Decrement (D) Magnification Factor

A fluid in equilibrium cannot sustain : (A) tensile stress (B) compressive stress (C) shear stress (D) bending stress

A systematic job improvement sequence will consist of : (A) motion study (B) time study (C) job enrichment (D) all of these

Euler’s dimensionless number relates the following : (A) Inertial force and gravity (B) Viscous force and Inertial force (C) Pressure force and Inertial force (D) Pressure force and viscous force

Military type of organisation is known as : (A) line organisation (B) functional organisation (C) line and staff organisation (D) line, staff and functional organisation

A casting defect which occurs near the ingates as rough lumps on the surface of a casting is known as 1. Shift 2. Sand wash 3. Swell 4. Scab

The property of sand due to which the sand grains stick together, is called 1. Collapsibility 2. Permeability 3. Cohesiveness 4. Adhesiveness

In die casting, machining allowance is 1. Small 2. Large 3. Very large 4. Not provided

The mode of deformation of the metal during spinning is 1.Bending 2.Stretching 3.Bending and stretching 4.Rolling and stretching

Structural sections such as rails, angles, I-beams are made by 1. Hot rolling 2. Hot drawing 3. Hot piercing 4. Hot extrusion

The process extensively used for making bolts and nuts is 1. Hot piercing 2. Extrusion 3. Cold peening 4. Cold heading