386. A mild steel plate has to be rolled in one pass such that the final plate thickness is 2/3rd of the initial thickness, with the entrance speed of 10 m/min and roll diameter of 500 mm. If the plate widens by 2% during rolling, the exit velocity (in m/min) is______.

1. 1. 14.6

   
   
   

   2. 14.8

   
   
   

   3. 14.7

   
   
   

   4. 14.9

   
   
   

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1. View Hint View Answer Discuss in Forum

   b₁ h₁ V₁ = b₂ h₂ V₂.
   

   	hi	=	2		b2	= 1.02
   	h1		3		b1

   
   

   v2 =	b1	×	h1	× h1
   	b2		h2

   
   

   v2 =	1	×	2	× 10
   	1.02		3

   
   V₂ = 14.7m/ min

   Correct Option: C

   b₁ h₁ V₁ = b₂ h₂ V₂.
   

   	hi	=	2		b2	= 1.02
   	h1		3		b1

   
   

   v2 =	b1	×	h1	× h1
   	b2		h2

   
   

   v2 =	1	×	2	× 10
   	1.02		3

   
   V₂ = 14.7m/ min

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387. In the deep drawing of cups, blanks show a tendency to wrinkle up around the periphery (flange). The most likely cause and remedy of the phenomenon are, respectively.

1. 1. Buckling due to circumferential compression; Increase blank holder pressure.

   
   
   

   2. High blank holder pressure and high friction; Reduce blank holder pressure and apply lubricant.

   
   
   

   3. High temperature causing increase in circumferential length; Apply coolant to blank.

   
   
   

   4. Buckling due to circumferential compression; decrease blank holder pressure.

   
   
   

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1. View Hint View Answer Discuss in Forum

   Due to circumferential compression buckling in circumference, by increasing blank holding force buckling decrease in lateral direction of load applied.

   Correct Option: A

   Due to circumferential compression buckling in circumference, by increasing blank holding force buckling decrease in lateral direction of load applied.

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388. A shell of 100 mm diameter and 100 mm height with the corner radius of 0.4 mm is to be produced by cup drawing. The required blank diameter is

1. 1. 118 mm

   
   
   

   2. 161 mm

   
   
   

   3. 224 mm

   
   
   

   4. 312 mm

   
   
   

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1. View Hint View Answer Discuss in Forum

   D = √d² + 4hd
   D = √100² + 4 × 400 × 100
   D = 224 mm

   Correct Option: C

   D = √d² + 4hd
   D = √100² + 4 × 400 × 100
   D = 224 mm

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389. Identify the stress strain in flange portion of a partially drawn cylindrical cup when deep drawing without a blank holder

1. 1. tensile in all three directions

   
   
   

   2. no stress in the flange at all, because there is no blank holder

   
   
   

   3. tensile stress in one direction and compressive stress in other direction

   
   
   

   4. tensile in two directions and compressive in third direction

   
   
   

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1. View Hint View Answer Discuss in Forum

   Tensile in Radial direction & compressive in circumferential direction.

   Correct Option: C

   Tensile in Radial direction & compressive in circumferential direction.

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390. In deep drawing of sheets, the values of limiting drawing ratio depends on

1. 1. percentage elongation of the sheet

   
   
   

   2. yield strength of the sheet

   
   
   

   3. type of press used

   
   
   

   4. thickness of sheet

   
   
   

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1. View Hint View Answer Discuss in Forum

   thickness of sheet

   Correct Option: D

   thickness of sheet

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