Question

The thimble of a screw gauge has 50 divisions. The spindle advances 1 mm when the screw is turned through two revolutions. What is the:

a) Pitch of the screw gauge?

b) Least count of the screw gauge?

Answer 1

Step 1: Given data

Distance moved in two complete revolutions$=1mm$

Number of divisions on the thimble of a screw gauge$=$Number of divisions on a circular scale$=50$

Step 2:Calculating pitch

We know the pitch is the distance moved by the spindle in one complete revolution

Since,

Distance moved in two complete revolutions$=1mm$

Therefore Pitch$\frac{1}{2}=0.5mm=0.05cm$

Hence the pitch is 0.05 cm

Step 3:Calculating least count

$$\begin{gathered} Leastcount=\frac{Pitch}{No.ofdivisions} \\ =\frac{0.05cm}{50} \\ =0.01cm \end{gathered}$$

Hence least count is 0.01 cm

Hence, the pitch is 0.05 cm and the least count is 0.01 cm.