156. Match List-I (welding problems) with List-II (Causes) and select the correct answer using the codes given below the lists:
     List-I
     A. Cracking of weld metal
     B. Cracking of base metal
     C. Porosity
     D. Inclusions
     List-II
     1. Excessive stresses
     2. High joint rigidity
     3. Failure to remove slag from previous deposit 4. Oxidation
     5. Excessive H2, O2, N2 in the welding atmosphere Codes:

1. 1. A B C D
      2 1 5 3
      

   
   
   

   2. A B C D
      3 4 2 1
      

   
   
   

   3. A B C D
      2 4 5 3
      

   
   
   

   4. A B C D
      3 1 4 2

   
   
   

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1. View Hint View Answer Discuss in Forum

   A – 2 B – 1 C – 5 D – 3

   Correct Option: D

   A – 2 B – 1 C – 5 D – 3

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157. The cold cracking susceptibility of the heat affected zone in an arc weld is influenced by
     P. Entrapped hydrogen
     Q. Residual stresses
     R. Martensitically transformation
     S. Slag inclusion

1. 1. P and S

   
   
   

   2. P, Q and S

   
   
   

   3. P, Q and R

   
   
   

   4. R and S

   
   
   

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1. View Hint View Answer Discuss in Forum

   Entrapped hydrogen creates obstacle in the diffusion of Carbon in interstitial site.
   

   Correct Option: C

   Entrapped hydrogen creates obstacle in the diffusion of Carbon in interstitial site.
   

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158. High speed electron beam welding is focused on the weld spot using

1. 1. vacuum lens

   
   
   

   2. inert gas lens

   
   
   

   3. optical lens

   
   
   

   4. magnetic lens

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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159. Welding application process
     List-I
     A. High reactive metals
     B. Long straight butt joint in thick sections
     C. Site weld of rails
     D. MS rods to plate like components
     List-II
     1. Ultrasonic
     2. Thermit
     3. Electron beam
     4. Submerged arc
     5. Stud

1. 1. A - 3, B - 4, C - 2, D - 5

   
   
   

   2. A - 5, B - 4, C - 2, D - 3

   
   
   

   3. A - 3, B - 2, C - 4, D - 5

   
   
   

   4. A - 4, B - 3, C - 2, D - 5

   
   
   

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1. View Hint View Answer Discuss in Forum

   A. High Reactive metals - EBM
   B. Long straight butt joint - SAW
   C. Site weld of rails - Thermit
   D. MS Rods to plate like components- Stud

   Correct Option: A

   A. High Reactive metals - EBM
   B. Long straight butt joint - SAW
   C. Site weld of rails - Thermit
   D. MS Rods to plate like components- Stud

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160. The type of coated electrode most widely used for welding low carbon steel is

1. 1. cellulose

   
   
   

   2. acidic

   
   
   

   3. rutile

   
   
   

   4. oxide

   
   
   

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1. View Hint View Answer Discuss in Forum

   Rutile: High proportion of titanium oxide create a shielding gas like co₂ This flux also contains cellulose.
   

   Correct Option: C

   Rutile: High proportion of titanium oxide create a shielding gas like co₂ This flux also contains cellulose.
   

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