Question

50 mm diameter disc is to be punched out from a carbon steel sheet 1.0 mm thick. The diameter of the punch should be. (Take clearance as 3% of disc thickness).
49.94 mm
50.00 mm
50.075 mm
None of these

Answer 1

answer : 49.94mm

explanation :  using formula,

The diameter of punch = diameter of disc - 2 × clearness

here it is given that ,

diameter of disc = 50mm

and clearance = 3% of disc thickness

= 3% of 1mm [ as thickness of disc = 1mm]

= 3 × 1/100 = 0.03 mm

so, The diameter of punch = 50mm - 2 × 0.03mm

= 50mm - 0.06mm

= 49.94 mm

hence, The diameter of punch should be 49.94 mm.

Answer 2

Answer:

Option 1st is correct that is 49.94 mm

Step-by-step explanation:

Given: 50 mm Diameter Disc and 1 mm thick

To find: Diameter of the punch

The diameter of punch = diameter of disc - 2 × clearness

here it is given that ,

clearance = 3% of disc thickness

                = 3% × 1 = 3/100 × 1 = 0.03 mm

Thus, we get

The diameter of punch = 50 - 2 × 0.03 = 50 - 0.06 = 49.94 mm

Therefore, Option 1st is correct that is 49.94 mm