Q.
In an experiment to find out the diameter of wire using screw gauge, the following observation were noted :
(a) Screw moves $0.5 \,mm$ on main scale in one complete rotation
(b) Total divisions on circular scale $=50$
(c) Main scale reading is $2.5 \,mm$
(d) $45^{\text {th }}$ division of circular scale is in the pitch line
(e) Instrument has $0.03 \, mm$ negative error
Then the diameter of wire is :
Solution: