- Home
- Standard 11
- Physics
A screw gauge with a pitch of $0.5 \ mm$ and a circular scale with $50$ divisions is used to measure the thickness of a thin sheet of Aluminium. Before starting the measurement, it is found that wen the two jaws of the screw gauge are brought in contact, the $45^{th} $division coincides with the main scale line and the zero of the main scale is barely visible. What is the thickness of the sheet (in $mm$) if the main scale reading is $0.5\ mm$ and the $25^{th}$ division coincides with the main scale line
$0.70$
$0.50$
$0.75$
$0.80$
Solution
$L.C = \frac{{0.5}}{{50}} = 0.001\,mm$
zero error $= 5 \times 0.001 = 0.05$ mm negative
Reading $= \left( {0.5 + 25 \times 0.01} \right) + 0.05 = 0.80$ mm
Similar Questions
Diameter of a steel ball is measured using a Vernier callipers which has divisions of $0. 1\,cm$ on its main scale $(MS)$ and $10$ divisions of its vernier scale $(VS)$ match $9$ divisions on the main scale. Three such measurements for a ball are given as
S.No. | $MS\;(cm)$ | $VS$ divisions |
$(1)$ | $0.5$ | $8$ |
$(2)$ | $0.5$ | $4$ |
$(3)$ | $0.5$ | $6$ |
If the zero error is $- 0.03\,cm,$ then mean corrected diameter is ……….. $cm$