251. Disposable patterns are made of

1. 1. wood

   
   
   

   2. rubber

   
   
   

   3. metal

   
   
   

   4. polystyrene

   
   
   

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1. View Hint View Answer Discuss in Forum

   Thermosetting plastic

   Correct Option: B

   Thermosetting plastic

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252. Which of the following materials requires the largest shrinkage allowance, while making a pattern for casting

1. 1. Aluminium

   
   
   

   2. Brass

   
   
   

   3. Cast iron

   
   
   

   4. Plain carbon steel

   
   
   

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1. View Hint View Answer Discuss in Forum

   Brass

   Correct Option: B

   Brass

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253. Match the following
     A. Sand casting
     B. Plaster mould casting
     C. Shell mould casting
     D. Investment casting
     1. Symmetrical and circular shapes only
     2. Parts have hardened skins and soft interior
     3. Minimum post casting process
     4. Parts have soft skin and hard interior
     5. Parts have a tendency to warp
     6. Suitable only for nonferrous metals

1. 1. A – 4, B – 6, C – 2, D – 2

   
   
   

   2. A – 5, B – 6, C – 2, D – 3

   
   
   

   3. A – 5, B – 3, C – 2, D – 6

   
   
   

   4. A – 4, B – 6, C – 2, D – 1

   
   
   

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1. View Hint View Answer Discuss in Forum

   A – 5, B – 6, C – 2, D – 3

   Correct Option: B

   A – 5, B – 6, C – 2, D – 3

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254. Only 4 pairs can be matched Casting process
     A. Investment casting
     B. Die casting
     C. Centrifugal casting
     D. Drop forging
     E. Extrusion
     F. Shell moulding
     Product
     1. Turbine rotors
     2. Turbine blades
     3. Connecting rods
     4. Galvanized iron pipes
     5. Cast iron pipes
     6. Carburetor body

1. 1. A – 4, B – 3, C – 2, D – 5

   
   
   

   2. A – 2, B – 3, C – 2, D – 5

   
   
   

   3. A – 1, B – 3, C – 2, D – 4

   
   
   

   4. A – 2, B – 5, C – 2, D –1

   
   
   

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1. View Hint View Answer Discuss in Forum

   A – 2, B – 3, C – 2, D – 5

   Correct Option: B

   A – 2, B – 3, C – 2, D – 5

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255. Centrifugally casted products have

1. 1. large grain structure with high porosity

   
   
   

   2. fine grain structure with high density

   
   
   

   3. fine grain structure with low density

   
   
   

   4. segregation of slug toward the outer skin of the casting

   
   
   

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1. View Hint View Answer Discuss in Forum

   Due to faster cooling rate of casting

   Correct Option: B

   Due to faster cooling rate of casting

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