List of top Materials, Manufacturing & Industrial Engineering Questions asked in GATE Mechanical Engineering

The welding process commonly used for fabricating tailor-welded blanks of dissimilar thickness for automotive applications is:

A project involves eight activities with the precedence relationship and duration as shown in the table below. The slack for the activity D is __________ hours (answer in integer). 


 

A company uses 3000 units of a part annually. The units are priced as given in the table below. It costs ₹150 to place an order. Carrying costs are 40 percent of the purchase price per unit on an annual basis. The minimum total annual cost is ₹ _________ (rounded off to 1 decimal place).


 

Cylindrical workpieces of diameter 60 mm and length 400 mm are machined on a lathe at a cutting speed of 25 m/min and a feed of 0.2 mm/rev. The Taylor’s tool life parameters \(C\) and \(n\) for this setup are 75 and 0.25, respectively. The tool changing time is 3 minutes. With a labor and overhead cost of ₹5 per minute, the tool changing cost per piece is ₹_________ (rounded off to 2 decimal places).

An isotropic brittle material is tested in the universal testing machine. The stress-strain diagram for the material shows a bi-linear elastic behavior as shown in the figure given below. The strain energy density is _________ MJ m\(^{-3}\) (rounded off to 2 decimal places).


 

A simply supported beam of length 1 m is subjected to a uniformly distributed bending moment of 1 N m per meter throughout the length as shown in the figure. The bending moment at the mid-point of the beam is __________ N m (rounded off to the nearest integer).


 

The state of stress at a point is shown in the figure given below. Under plane stress assumption, the normal strain along the thickness direction (\(\epsilon_{zz}\)) is _________ (rounded off to 2 decimal places).


 

Consider a Pelton wheel of 1 m diameter. The magnitude of relative velocity of water at the bucket inlet is the same as the magnitude of relative velocity of water at the bucket exit. The absolute speed of water at the bucket inlet is 125.66 m/s\(^{-1}\). For maximum power output from the Pelton wheel, the rpm of the Pelton wheel is (rounded off to 1 decimal place).

In relation to additive manufacturing, match the following:


 

Wire drawing operation is performed on a perfectly plastic metal without any strain hardening. Assuming no friction and no redundant work, the maximum possible percentage reduction in area in a single pass is closest to:

Match the mold elements in the casting process with the most suitable function: 


 

Considering the actual demand and the forecast for a product given in the table below, the mean forecast error and the mean absolute deviation, respectively, are:


 

A liquid metal is poured in a mold cavity of size 200 mm \(\times\) 200 mm \(\times\) 200 mm. The cooling is uniform in all directions with NO additional compensation for shrinkage. Considering the volumetric shrinkage during solidification and solid contraction as 7% and 8%, respectively, the length of the cube edge after cooling down to the room temperature is _________ mm (rounded off to 1 decimal place).
A metallic square plate is subjected to a uniform hydrostatic pressure (\(P\)). Choose the correct Mohr's circle representing the state of stress at any point in the plate from the options given below. For the Mohr's circle, normal stress is positive towards the right and shear stress is positive in the upward direction.
When assembled, the hole \(30^{+0.030}_{0.000}\) mm and shaft \(30^{+0.020}_{-0.020}\) mm will result in:
Ceramics and glass are machined by:
In computer aided design (CAD), solid models can be constructed using:
Among the following surface hardening processes, steel is heated to the lowest temperature in:
Two metal parts (a cylinder and a cube) of same volume are cast under identical conditions. The diameter of the cylinder is equal to its height. The ratio of the solidification time of the cube to that of the cylinder is _________ (rounded off to 2 decimal places).
Assume that solidification time follows Chvorinov’s rule with an exponent of 2.
The yield stress of a metal in uniaxial tension is 200 MPa. According to von Mises yield criterion, the yield stress (in MPa) of the metal in pure shear is closest to:
In a DC arc welding process, open-circuit voltage is 100 V and short-circuit current is 1000 A. Arc voltage varies as $V = 10 + 5l$, where $l$ is arc length in mm. The maximum available arc power during the process is ____________ kVA (in integer).
The best size wire is fitted in a groove of a metric screw such that the wire touches the flanks of the thread on the pitch line. The pitch $p = 4$ mm and the included angle of the thread is $60^\circ$. The diameter of the best size wire is ____________ mm (round off to 2 decimal places).
A straight–teeth horizontal slab milling cutter has 4 teeth and diameter $D = 200$ mm. Rotational speed = 100 rpm, Feed = 1000 mm/min, Workpiece width $w = 100$ mm. Cutting force/tooth = $F = K\, t_c\, w$, $K = 10$ N/mm$^2$. Depth of cut is $d = D/2$, and the maximum cutting force is __________ kN (round off to one decimal place).
In an orthogonal machining operation, the cutting and thrust forces are equal. Uncut chip thickness = 0.5 mm, shear angle = \(15^\circ\), rake angle = \(0^\circ\), width of cut = 2 mm. The work material is perfectly plastic with yield shear strength \(500\ \text{MPa}\). Find the cutting force (nearest integer).
A shaft carries a thin pulley of radius \( r = 0.4\ \text{m} \) at end C. Taut and slack belt tensions are \( T_1 = 300\ \text{N} \) and \( T_2 = 100\ \text{N} \). Allowable shear stress in the shaft is 80 MPa. The shaft length segments are \( AB = BC = L = 0.5\ \text{m} \). Neglecting shock and fatigue and using maximum shear stress theory, find the minimum shaft diameter (in mm).