List of top Materials, Manufacturing & Industrial Engineering Questions

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).

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).

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).

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).

Parts P1--P7 are machined first on a milling machine and then polished at a separate machine. Using the information in the following table, the minimum total completion time required for carrying out both the operations for all 7 parts is ____________________ hours.

A manufacturing unit produces two products P1 and P2. For each piece of P1 and P2, the table below provides quantities of materials M1, M2, and M3 required, and also the profit earned. The maximum quantity available per day for M1, M2 and M3 is also provided. The maximum possible profit per day is ₹ ________________.

Which of these processes involve(s) melting in metallic workpieces?

Consider sand casting of a cube of edge length $a$. A cylindrical riser is placed at the top of the casting. Assume solidification time, $t_s \propto V/A$, where $V$ is the volume and $A$ is the total surface area dissipating heat. If the top of the riser is insulated, which of the following radius/radii of riser is/are acceptable?

Which one of the following CANNOT impart linear motion in a CNC machine?

Match the additive manufacturing technique in Column I with its corresponding input material in Column II.

A shaft of diameter $25^{-0.04}_{-0.07}$ mm is assembled in a hole of diameter $25^{+0.02}_{+0.00}$ mm. Match the allowance and limit parameter in Column I with its corresponding quantitative value in Column II for this shaft–hole assembly.

Which one of the following is the definition of ultimate tensile strength (UTS) obtained from a stress-strain test on a metal specimen?

Fluidity of a molten alloy during sand casting depends on its solidification range. The phase diagram of a hypothetical binary alloy of components A and B is shown in the figure with its eutectic composition and temperature. All the lines in this phase diagram, including the solidus and liquidus lines, are straight lines. If this binary alloy with 15 weight % of B is poured into a mould at a pouring temperature of 800\,$^\circ$C, then the solidification range is ________________.

A 76.2 mm gauge block is used under one end of a 254 mm sine bar with roll diameter of 25.4 mm. The height of gauge blocks required at the other end of the sine bar to measure an angle of 30° is $\underline{\hspace{2cm}}$ mm (round off to two decimal places).

The thickness, width and length of a metal slab are 50 mm, 250 mm and 3600 mm, respectively. A rolling operation on this slab reduces the thickness by 10% and increases the width by 3%. The length of the rolled slab is $\underline{\hspace{2cm}}$ mm (round off to one decimal place).

In pure orthogonal turning by a zero rake angle single point carbide cutting tool, the shear force has been computed to be 400 N. The cutting velocity, $ V_c = 100 \ \text{m/min} $, depth of cut, $ t = 2.0 \ \text{mm} $, feed, $ s_0 = 0.1 \ \text{mm/revolution} $ and chip velocity, $ V_f = 20 \ \text{m/min} $, the shear strength $ \tau_s $ of the material will be $\underline{\hspace{2cm}}$ MPa (round off to two decimal places).

A surface grinding operation has been performed on a Cast Iron plate having dimensions 300 mm (length) $ \times $ 10 mm (width) $ \times $ 50 mm (height). The grinding was performed using an alumina wheel having a wheel diameter of 150 mm and wheel width of 12 mm. The grinding velocity used is 40 m/s, table speed is 5 m/min, depth of cut per pass is 50 μm and the number of grinding passes is 20. The average tangential and average normal force for each pass is found to be 40 N and 60 N respectively. The value of the specific grinding energy under the aforesaid grinding conditions is $\underline{\hspace{2cm}}$ J/mm³ (round off to one decimal place).

A spot welding operation performed on two pieces of steel yielded a nugget with a diameter of 5 mm and a thickness of 1 mm. The welding time was 0.1 s. The melting energy for the steel is 20 J/mm³. Assuming the heat conversion efficiency as 10%, the power required for performing the spot welding operation is $\underline{\hspace{1cm}}$ kW (round off to two decimal places).

A cast product of a particular material has dimensions 75 mm $\times$ 125 mm $\times$ 20 mm. The total solidification time for the cast product is found to be 2.0 minutes as calculated using Chvorinov's rule having the index, $n = 2$. If under the identical casting conditions, the cast product shape is changed to a cylinder having diameter = 50 mm and height = 50 mm, the total solidification time will be $\underline{\hspace{1cm}}$ minutes (round off to two decimal places).

Daily production capacity of a bearing manufacturing company is 30000 bearings. The daily demand of the bearing is 15000. The holding cost per year of keeping a bearing in the inventory is ₹ 20. The setup cost for the production of a batch is ₹ 1800. Assuming 300 working days in a year, the economic batch quantity in number of bearings is $\underline{\hspace{1cm}}$ (in integer).

A factory produces $ m $ (i = 1, 2, ..., m) products, each of which requires processing on $ n $ (j = 1, 2, ..., n) workstations. Let $ a_{ij} $ be the amount of processing time that one unit of the $ i^{th} $ product requires on the $ j^{th} $ workstation. Let the revenue from selling one unit of the $ i^{th} $ product be $ r_i $ and $ h_i $ be the holding cost per unit per time period for the $ i^{th} $ product. The planning horizon consists of $ T $ (t = 1, 2, ..., T) time periods. The minimum demand that must be satisfied in time period $ t $ is $ d_{it} $, and the capacity of the $ j^{th} $ workstation in time period $ t $ is $ c_{jt} $. Consider the aggregate planning formulation below, with decision variables $ S_{it} $ (amount of product $ i $ sold in time period $ t $), $ X_{it} $ (amount of product $ i $ manufactured in time period $ t $) and $ I_{it} $ (amount of product $ i $ held in inventory at the end of time period $ t $). \[ \text{max} \sum_{t=1}^{T} \sum_{i=1}^{m} (r_i S_{it} - h_i I_{it}) \] subject to \[ S_{it} \ge d_{it} \forall i, t \] <capacity constraint>
<inventory balance constraint>
\[X_{it}, S_{it}, I_{it} \ge 0; \, I_{i0} = 0 \] The capacity constraints and inventory balance constraints for this formulation are

The demand and forecast of an item for five months are given in the table.

\[ \begin{array}{|c|c|c|} \hline \text{Month} & \text{Demand} & \text{Forecast} \\ \hline \text{April} & 225 & 200 \\ \text{May} & 220 & 240 \\ \text{June} & 285 & 300 \\ \text{July} & 290 & 270 \\ \text{August} & 250 & 230 \\ \hline \end{array} \]

The Mean Absolute Percent Error (MAPE) in the forecast is $\underline{\hspace{1cm}}$ % (round off to two decimal places).

The allowance provided in between a hole and a shaft is calculated from the difference between

The machining process that involves ablation is