1. Tardigrade
  2. Question
  3. Physics
  4. A spectrometer gives the following reading when used to measure the angle of a prism. Main scale reading: 58.5 degree Vernier scale reading: 09 divisions Given that 1 division on main scale corresponds to 0.5 degree. Total divisions on the vernier scale is 30 and match with 29 divisions of the main scale. The angle of the prism from the above data :

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. A spectrometer gives the following reading when used to measure the angle of a prism.
Main scale reading : 58.5 degree
Vernier scale reading : 09 divisions
Given that 1 division on main scale corresponds to 0.5 degree. Total divisions on the vernier scale is 30 and match with 29 divisions of the main scale. The angle of the prism from the above data :

AIEEEAIEEE 2012Physical World, Units and Measurements

Solution:

$30 V.S.D. \rightarrow 29 M.S.D.$
$1 V.S.D. \rightarrow \frac{29}{30}M.S.D.$
$=\frac{29}{30}\times0.5$
least count of vernier = 1 M.S.D. - 1 V.S.D.
$=0.5^{º}-\frac{29}{30}\times0.5^{º}
=\frac{0.5º}{30}$
Reading of vernier = M.S. reading + V.S reading × least count
$=58.5{º}+9\times\frac{0.5{º}}{30}$
$=58.65$