Question

To what degree the edges of optical flats are bevelled?

(a) 30^o

(b) 45^o

(c) 60^o

(d) 90^o

I have been asked this question in a job interview.

I need to ask this question from Optical Flats topic in chapter Measurement by Light-Wave Interference of Engineering Metrology

Answer 1

Right option is (b) 45^o

For explanation I would say: Edges of optical flats are generally bevelled to 45^o by suitable grinding and polishing to make edges free from any chips. Working surfaces of optical flats are finished by polishing and lapping process and the cylindrical surfaces are finished by grinding.