Quiz:Mechanical Engineering 04 June 2020

Quiz: Mechanical Engineering
Exam: UPPSC AE
Topic: Manufacturing Engineering

Each question carries 3 mark.
Negative marking: 1 mark
Time: 10 Minute

Q1. The atmosphere required in the furnace for nitriding the steel component is of
(a) Liquid nitrogen
(b) Nascent nitrogen
(c) Ammonia
(d) Graphite

Q2. Refractoriness of the moulding sand can be increased by
(a) Increasing the grain size
(b) Decreasing the grain size
(c) Increasing the water content
(d) Increasing the clay content

Q3. Which condition is non-favourable for continuous chips?
(a) Low feed and depth of cut
(b) Brittle work piece
(c) High speed
(d) High back rack angle

Q4. Swab is
(a) a welding defect
(b) a tool used in foundry
(c) a gear cutter
(d) a forging die

Q5. In submerged arc welding, an arc is produced between:
(a) Carbon electrode and the work-piece
(b) Metal electrode and the work-piece
(c) Bare metal electrode and the work-piece
(d) Two tungsten electrodes and the work-piece

Q6. A 50 mm diameter disc is to be punched out from a carbon steel sheet 1.0 mm thick. The diameter of the punch should be
(a) 42.925 mm
(b) 50.00 mm
(c) 50.075 mm
(d) None of these

Q7. Among the following for which operation, the slowest speed is selected in lathe?
(a) Facing
(b) Taper turning
(c) Thread cutting
(d) Straight turning

Q8. Abrasive grain size of 10 on grinding wheel refers to:
(a) Fine grain wheel
(b) Coarse grain wheel
(c) Medium grain wheel
(d) Very fine grain wheel

Q9. Plug rolling is used to
(a) produce seamless tube
(b) reduce wall thickness and increase diameter of tubes
(c) produce collapsible tubes
(d) increase wall thickness of tubes

Q10. Which type of gears can be manufactured by extrusion process?
(a) Bevel gears
(b) Herringbone gears
(c) Worm gears
(d) None of these

Solutions

S1. Ans.(c)
Sol. The atmosphere required in the furnace for nitriding the steel component is of ammonia. Nitriding is a heat treatment process that diffuse nitrogen into the surface of a metal to create a case-hardened surface.

S2. Ans.(a)
Sol. Refractoriness of the moulding material is the ability to withstand high temperature of molten metal, so that it does not get fused with the metal.
It can be increased by increasing the grain size.

S3. Ans.(b)
Sol. Cutting of a brittle material is non favourable for continuous chips formation. Continuous chips form in ductile material.

S4. Ans.(b)
Sol. Swab is a tool that is used in foundry shop and used for applying water to the mould around the edge of the pattern. This prevents the sand edges from crumbling.

S5. Ans.(c)
Sol. Submerged arc welding, is a common arc welding process, it involves the formation of arc between a continuously fed bare electrode and the work-piece.

S6. Ans.(d)
Sol. We know that clearance of low carbon steel = 3 % of thickness
C=0.03×1
C=0.03 mm
For punching operation,
Punch Size = Blank size-2C=50-2×0.03
Punch size = 50-0.06
Punch size = 49.94 mm

S7. Ans.(c)
Sol. Thread cutting used for forming threads on a workpiece, is done at the slowest speed in lathe machine.

S8. Ans.(b)
Sol. Abrasive grain size of 10 on grinding wheel refers to coarse grain size. Generally, grain sizes of grinding wheel are 10-24(coarse),30-60(medium),80-200(fine) and 220-600(very fine).

S9. Ans.(b)
Sol. Plug rolling is used to reduce the thickness of wall and increase the diameter of the tubes.

S10. Ans.(b)
Sol. Double helical gears or Herringbone gears can be easily manufactured by extrusion process.

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