711. During gas welding of copper sheets a neutral flame was used consuming 8 litres of acetylene. But the weld was found to be defective. So it was rewelded using an oxidizing flame. The likely consumption of oxygen in litres will be
     

1. 1. 6
      

   
   
   

   2. 8
      

   
   
   

   3. 10
      

   
   
   

   4. 16
      

   
   
   

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   2 : 1 Ratio is maintained means 16 liters of oxygen will be used.
   

   Correct Option: C

   2 : 1 Ratio is maintained means 16 liters of oxygen will be used.
   

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712. In welding a mild steel sheet using an oxyacetylene flame, the total amount of acetylene consumed was 8.0 litres, the oxygen consumption from the cylinder is
     

1. 1. 8 litres
      

   
   
   

   2. 16 litres
      

   
   
   

   3. 20 litres
      

   
   
   

   4. 24 litres

   
   
   

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   NA

   Correct Option: A

   NA

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713. In welding brass with oxyacetylene flame, the type of flame used is _________ .

1. 1. oxidising

   
   
   

   2. reducing

   
   
   

   3. oxidising and reducing

   
   
   

   4. None of these

   
   
   

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   Must use an oxidising flame, fuming is virtually eliminated.

   Correct Option: A

   Must use an oxidising flame, fuming is virtually eliminated.

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714. In an electrical discharge machining process, the breakdown voltage across inter electrode gap (IEG) is 200V and the capacitance of the RC circuit is 50 μF. The energy (in J) released per spark across the IEG is ____

1. 1. 15 J

   
   
   

   2. 1.01 J

   
   
   

   3. 12 J

   
   
   

   4. 1 J

   
   
   

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   Energy =	1	CV2
   	2

   
   

   E =	1	× 50 × 10-6 × (200)2
   	2

   
   E = 1 J

   Correct Option: D

   Energy =	1	CV2
   	2

   
   

   E =	1	× 50 × 10-6 × (200)2
   	2

   
   E = 1 J

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

1. 1. 3500°C
      

   
   
   

   2. 3200°C
      

   
   
   

   3. 2900°C
      

   
   
   

   4. 2550°C

   
   
   

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1. View Hint View Answer Discuss in Forum

   

   Correct Option: B

   

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