481. The diameter of a recessed ring was measured by using two spherical balls of diameter d₁ = 60 mm and d₂ = 40 mm as shown in the figure.
     
     The distance H₁ = 35.55 mm and H₂ = 20.55 mm. The diameter (D, in mm) of the ring gauge is ________

1. 1. 93 mm.

   
   
   

   2. 23 mm.

   
   
   

   3. 91 mm.

   
   
   

   4. 83 mm.

   
   
   

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1. View Hint View Answer Discuss in Forum

   Dring = d1sec	θ	+ 2(h1 + r1)tan	θ
   	2		2

   
   ∴  θ = 60º = 4 × sec 30 + 2 (20.55 + 20) tan 30°
   D_ring = 93 mm.

   Correct Option: A

   Dring = d1sec	θ	+ 2(h1 + r1)tan	θ
   	2		2

   
   ∴  θ = 60º = 4 × sec 30 + 2 (20.55 + 20) tan 30°
   D_ring = 93 mm.

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482. In an interchangeable assembly, shafts of size 25.000^{−0.010+0.040} mm mate with holes of size 0.020 25.000^{−0.020+0.030}mm. The maximum interference (in microns) in the assembly is

1. 1. 40

   
   
   

   2. 30

   
   
   

   3. 20

   
   
   

   4. 10

   
   
   

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1. View Hint View Answer Discuss in Forum

   Maximum interference = Maximum size of shaft – Minimum size of hole = 25.040 – 25.020 = 20 μm

   Correct Option: C

   Maximum interference = Maximum size of shaft – Minimum size of hole = 25.040 – 25.020 = 20 μm

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483. A hole is of dimension φ9^+0+0.015 mm. The corresponding shaft is of dimension φ9^+0.001+0.010 The resulting assembly has

1. 1. loose running fit

   
   
   

   2. close running fit

   
   
   

   3. transition fit

   
   
   

   4. interference fit

   
   
   

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1. View Hint View Answer Discuss in Forum

   Transition Fit.
   

   Correct Option: C

   Transition Fit.
   

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484. A single point cutting tool with 12° rake angle is used for orthogonal machining of a ductile material. The shear plane angle for the theoretically minimum possible shear strain to occur

1. 1. 51

   
   
   

   2. 45

   
   
   

   3. 30

   
   
   

   4. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   From Ernest & Merchant’s Theory for minimum power consumption:
   

   φ =	90 + α	=	90 + 12	= 51°
   	2		2

   
   φ = 51°

   Correct Option: A

   From Ernest & Merchant’s Theory for minimum power consumption:
   

   φ =	90 + α	=	90 + 12	= 51°
   	2		2

   
   φ = 51°

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485. lf the number of double strokes per minute in a shaper is calculated by (0.643 × Cutting speed in mm/min)/length of the stroke in m. Then the return speed is faster than the cutting speed by

1. 1. 40%

   
   
   

   2. 60%

   
   
   

   3. 80%

   
   
   

   4. 100%

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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