296. Assertion (A): Basic hole system is advocated by Indian Standards for fit design.
     Explanation (E): Holes can be produced to any size

1. 1. Both A and E are correct and E explains A

   
   
   

   2. Both A and E are true but E does not explains A

   
   
   

   3. A is true but E is false

   
   
   

   4. A is false but E is true

   
   
   

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1. View Hint View Answer Discuss in Forum

   Both A and E are correct and E explains A

   Correct Option: A

   Both A and E are correct and E explains A

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297. Flatness of slip gauges is checked with

1. 1. Interferometer

   
   
   

   2. Optical flat

   
   
   

   3. Electronic comparator

   
   
   

   4. Linear bar and bevel protractor

   
   
   

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1. View Hint View Answer Discuss in Forum

   Interferometer

   Correct Option: A

   Interferometer

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298. In a casting process, a vertical channel through which molten metal flows downward from pouring basin to runner for reaching the mould cavity is called

1. 1. riser

   
   
   

   2. blister

   
   
   

   3. pin hole

   
   
   

   4. sprue

   
   
   

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1. View Hint View Answer Discuss in Forum

   sprue

   Correct Option: D

   sprue

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299. Assume that the surface roughness profile is triangular as shown schematically in the figure. If the peak to valley height is 20 μ m, the central line average surface roughness R₀ (in μ m) is
     

1. 1. 5

   
   
   

   2. 6.67

   
   
   

   3. 10

   
   
   

   4. 20

   
   
   

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1. View Hint View Answer Discuss in Forum

   Ra =	hmax	=	20	= 5μm.
   	4		4

   Correct Option: A

   Ra =	hmax	=	20	= 5μm.
   	4		4

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300. Metric thread of 0.8 mm pitch is to be cut on a lathe. Pitch of the lead screw is 1.5 mm. If the spindle rotates at 1500 rpm, the speed of rotation of the lead screw (rpm) will be________.

1. 1. 900

   
   
   

   2. 700

   
   
   

   3. 800

   
   
   

   4. 400

   
   
   

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1. View Hint View Answer Discuss in Forum

   Pitch = 0.8 mm
   N_t = 1500 rpm
   P_s = 1.5 mm
   N_s × P₃ × Z_z = N_t × P_t × Z_t
   [Z_s = Z_t = 1]
   

   Ns =	1500 × 0.8 × 1
   	1.5 × 1

   
   N_s = 800 rpm

   Correct Option: C

   Pitch = 0.8 mm
   N_t = 1500 rpm
   P_s = 1.5 mm
   N_s × P₃ × Z_z = N_t × P_t × Z_t
   [Z_s = Z_t = 1]
   

   Ns =	1500 × 0.8 × 1
   	1.5 × 1

   
   N_s = 800 rpm

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