Answer the following:

(a) You are given a thread and a metre scale. How will you estimate the diameter of the thread ?

(b) A screw gauge has a pitch of 1.0 mm and 200 divisions on the circular scale. Do you think it is possible to increase the accuracy of the screw gauge arbitrarily by increasing the number of divisions on the circular scale ?

© The mean diameter of a thin brass rod is to be

measured by vernier calipers. Why is a set of 100 measurements of the diameter expected to yield a more reliable estimate than a set of 5 measurements only ?

(a) By winding the thread on in close turns on a pencil and using the formula i.e.

Diameter = Averagelength/No. of turns

2.Yes, by increasing the number of divisions on circular scale as

least count =Pitch/No. of divisions on circular scale

3.Random error is reduced on taking large number of observations.