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# Production Engineering

1.

For generating a Coon’s surface we require

Coon’s surface is obtained by blending four boundary curves. The main advantage of Coon’s surface is its ability to fit a smooth surface through digitized points in space such as those used in reverse engineering.

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2.

In ECM, the material removal is due to

In ECM, the principal of electrolysis is used to remove metal from the work-piece. The material removal is due to ion displacement. The principal of electrolysis is based on Faraday’s law of electrolysis.

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3.

Work speed of circular electrode of 220 mm diameter for carrying out seam welding at 4 welds per cm on 1.6 mm thick mild steel tube. Welding cycle consists of 3 cycles ‘on’ and 2 cycles ‘off’ Power supply is at 50 Hz. Calculate R.P.M. and energy requirement of the above circular electrodes assuming effective resistance between electrodes as 100 ohm.

Weld per min = (frequency × 60)/ (cycles for weld + interval cycles)
= (50 × 60)/ (3 + 2) = 600 welds/ min.
Work speed (mm / min) = (welds/ min) / weld required per mm
= 600 / (4/10) = 1500 mm/ min.
Therefore, RPM of electrode = work speed in mm per min/ π × electrode diameter in mm
1500/ (3.14 × 220) = 2.17 rpm.
For 1.6 mm thick M.S. Plate, current requirement is around 10,000 amperes
Therefore, Energy required = I⊃2;RT = (10,000⊃2;) × 100 × (3/ 50) = 600 Joules.

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4.

Which among the NC operations given below are continuous path operations?

Arc Welding (AW), Drilling (D), Laser Cutting of Sheet Metal (LC), Milling (M), Punching in Sheet Metal (P), Spot Welding (SW)

Arc welding, Laser cutting of sheet and milling operations are the continuous path operations.

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5.

The capacity of a material to be welded under the imposed fabrication conditions into a specific, suitably designed structure and to perform satisfactorily in the intended service is known as?

Weldability is the capacity of a material to be welded under the imposed fabrication conditions into a specific, suitably designed structure and to perform satisfactorily in the intended service.

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6.

In abrasive jet machining, as the distance between the nozzle tip and the work surface increases, the material removal rate

The material removal rate is first increases because of area of jet increase than becomes stable and then decreases due to decrease in jet velocity.

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7.

The strength of a brazed joint

We know that, the strength of the brazed joint depends on (a) joint design and (b) the adhesion at the interfaces between the work piece and the filler metal. The strength of the brazed joint increases up to certain gap between the two joining surfaces beyond which it decreases

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8.

In Oxyacetylene gas welding, temperature at the inner cone of the flame is around

In OAW, Acetylene (C₂H₂) produces higher temperature (in the range of 3200° C) than other gases, (which produce a flame temperature in the range of 2500° C) because it contains more available carbon and releases heat when its components (C & H) dissociate to combine with O₂ and burn.

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9.

Which one of the following is a solid state joining process?

Friction welding is defined as “A solid state welding process wherein coalescence is produced by heat obtained from mechanically induced sliding motion between rubbing surfaces.

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10.

In metal machining, the zone where the heat is generated due to friction between the moving chip and the tool face, is called