While measuring diameter of wire using screw gauge the following readings were noted. Main scale reading is 1 mm and circular scale reading is equal to 42 divisions. Pitch of screw gauge is 1 mm and it has 100 divisions on circular scale. The diameter of the wire is x50 mm. The value of x is :
- 42
- 71
- 21
- 142
Answer
(2) 71
Solution
Least count = pitchno. of circular divisions = 1100 = 0.01 mm
Diameter = MSR + CSR LC
= 1 + 42 0.01 = 1.42 mm
x50 = 1.42 x = 71
Answer: (2)