Question

Which is the wavelength of a spectrum which is used in surface contour test?

(a) 0.0005 mm

(b) 0.005 mm

(c) 0.05 mm

(d) 0.5 mm

I had been asked this question in exam.

My question comes from Surface Contour Test topic in section Measurement by Light-Wave Interference of Engineering Metrology

Answer 1

Correct answer is (a) 0.0005 mm

For explanation I would say: Surface contour test is used to study surface contours and an optical flat is kept at some inclination over the surface. Generally, daylight is used for this test. Wavelength of the spectrum of daylight is 0.0005 mm.