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 correspods 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:

Options

A. 58.59 degree
B. 58.77 degree
C. 58.65 degree
D. 59 degree

Answer

C

Explanation

`because" Reading of Vernier"="Main scale reading"+"Vernier scale reading"xx"least count."`
`"Thus, "R=58.5^(@)+9xx(0.5^(@))/(30) or R=58.65^(@)`