201. In a wire drawing operation, diameter of a Steel wire is reduced from 10 mm to 8 mm. The mean flow stress of the material is 400 MPa. The ideal force required for drawing (ignoring friction and redundant work) is

1. 1. 4.48 kN

   
   
   

   2. 8.97 kN

   
   
   

   3. 20.11 kN

   
   
   

   4. 31.41 kN

   
   
   

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1. View Hint View Answer Discuss in Forum

   D_i = 10 mm, D_i = 8mm
   σ₀
   = 400 MPa
   

   σd = σ0ln			Di			²
   			Df

   
   

   σd = 400ln			10			²
   			8

   
   σd = 178.51 MPa
   

   Ideal force = 178.51 × 106 ×	π	(0.008)²
   	4

   
   I deal force 8.97 KN

   Correct Option: B

   D_i = 10 mm, D_i = 8mm
   σ₀
   = 400 MPa
   

   σd = σ0ln			Di			²
   			Df

   
   

   σd = 400ln			10			²
   			8

   
   σd = 178.51 MPa
   

   Ideal force = 178.51 × 106 ×	π	(0.008)²
   	4

   
   I deal force 8.97 KN

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202. Cold shut is a defect in casting due to

1. 1. sand sliding from the cope surface

   
   
   

   2. internal voids or surface depression due to excessive gas trapped

   
   
   

   3. discontinuity resulting from hundred contraction

   
   
   

   4. two streams of material that are too cold to fuse properly

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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203. Manufacturing process
     A. Hot tears
     B. Porosity
     C. Sand inclusions
     D. Shrinkage cavity Property
     1. Mould restraint
     2. Inadequate risering
     3. High pouring temp
     4. Loosely rammed sand mould
     5. Gas entrapment

1. 1. A – 1, B – 5, C – 4, D – 2

   
   
   

   2. A – 2, B – 5, C – 4, D – 1

   
   
   

   3. A – 4, B – 5, C – 1, D – 2

   
   
   

   4. A – 1, B – 4, C – 5, D – 2

   
   
   

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1. View Hint View Answer Discuss in Forum

   A – 1, B – 5, C – 4, D – 2

   Correct Option: A

   A – 1, B – 5, C – 4, D – 2

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204. Low permeability moulds and low pouring temp of the molten metal causes blow holes. Defect in castings.(T/F)

1. 1. True

   
   
   

   2. False

   
   
   

   3. NA

   
   
   

   4. NA

   
   
   

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1. View Hint View Answer Discuss in Forum

   True

   Correct Option: A

   True

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205. Poor collapsibility of the mould leads to distortion cracks type of casting defect in aluminium castings. (T/F)

1. 1. True

   
   
   

   2. False

   
   
   

   3. NA

   
   
   

   4. NA

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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