# Using screw gauge of pitch 0.1 cm and 50 divisions on its circular scale,

Question:

Using screw gauge of pitch $0.1 \mathrm{~cm}$ and 50 divisions on its circular scale, the thickness of an object is measured. It should correctly be recorded as :

1. (1) $2.121 \mathrm{~cm}$

2. (2) $2.124 \mathrm{~cm}$

3. (3) $2.125 \mathrm{~cm}$

4. (4) $2.123 \mathrm{~cm}$

Correct Option: 1

Solution:

(1) Thickness $=$ M.S. Reading $+$ Circular Scale Reading (L.C.)

Here LC $=\frac{\text { Pitch }}{\text { Circular scale division }}=\frac{0.1}{50}=0.002 \mathrm{~cm}$ per

division

So, correct measurement is measurement of integral multiple of L.C.