16. It is desired to make a product having T-shaped cross-section from a rectangular aluminium block. Which one of the following processes is expected to provide the highest strength of the product?

1. 1. Welding

   
   
   

   2. Casting

   
   
   

   3. Metal forming

   
   
   

   4. Machining

   
   
   

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1. View Hint View Answer Discuss in Forum

   Metal forming of Aluminimum is easy because there is negligible strain hardening in Aluminium.

   Correct Option: C

   Metal forming of Aluminimum is easy because there is negligible strain hardening in Aluminium.

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17. Engineering strain of a mild steel sample is recorded as 0.100%. The true strain is

1. 1. 0.010%

   
   
   

   2. 0.055%

   
   
   

   3. 0.099%

   
   
   

   4. 0.101%

   
   
   

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1. View Hint View Answer Discuss in Forum

   Engg. strain ε =	0.1
   	100

   
   True strain ε_T = ln(1 + ε)
   

   = In		1 +	0.1
   			100

   
   = 0.0009995
   ε_T in % = 0.0995%

   Correct Option: C

   Engg. strain ε =	0.1
   	100

   
   True strain ε_T = ln(1 + ε)
   

   = In		1 +	0.1
   			100

   
   = 0.0009995
   ε_T in % = 0.0995%

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18. Match the following products with preferred manufacturing processes:
    

    Product	Process
    P. Rails	1. Blow molding
    Q. Engine crankshaft	2. Extrusion
    R. Aluminium channels	3. Forging
    S. PET water bottles	4. Rolling

1. 1. P-4, Q-3, R-1, S-2

   
   
   

   2. P-4, Q-3, R-2, S-1

   
   
   

   3. P-2, Q-4, R-3, S-1

   
   
   

   4. P-3, Q-4, R-2, S-1

   
   
   

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1. View Hint View Answer Discuss in Forum

   P–4, Q – 3, R –2, S – 1

   Correct Option: B

   P–4, Q – 3, R –2, S – 1

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19. The force requirement in a blanking operation of low carbon steel sheet is 5.0 kN. The thickness of the sheet is 't' and diameter of the blanked part is 'd'. For the same work material, if the diameter of the blanked part is increased to 1.5d and thickness is reduced to 0.4t, the new blanking force in kN is

1. 1. 3.0

   
   
   

   2. 4.5

   
   
   

   3. 6.7

   
   
   

   4. 0.8

   
   
   

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1. View Hint View Answer Discuss in Forum

   Let τ be the shear stress
   F = t × d × t = 5.0 kN
   F₁ = r × 1.5 d × 4 × t = .6 × 5 = 3 kN

   Correct Option: A

   Let τ be the shear stress
   F = t × d × t = 5.0 kN
   F₁ = r × 1.5 d × 4 × t = .6 × 5 = 3 kN

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20. In open-die forging, a disc of diameter 200 mm and height 60 mm is compressed without any barreling effect. The final diameter of the disc is 400 mm. The true strain is

1. 1. 1.986

   
   
   

   2. 1.686

   
   
   

   3. 1.386

   
   
   

   4. 0.602

   
   
   

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1. View Hint View Answer Discuss in Forum

   π	D²ih1 =	π	D²2h2
   4		4

   
   (200)² × 60 = 400² × 4₂.
   Change is length = 45 mm
   

   True stain = ln		h1		= In		60		= In 4
   		h2				15

   
   True strain 1.386

   Correct Option: C

   π	D²ih1 =	π	D²2h2
   4		4

   
   (200)² × 60 = 400² × 4₂.
   Change is length = 45 mm
   

   True stain = ln		h1		= In		60		= In 4
   		h2				15

   
   True strain 1.386

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