Two thin glass sheets (n = 1.5) are in contact on the other end and between the other end there is a sample when a wedgelike empty space containing air (n = 1.0) is formed (see picture). When the system is lighted with monochromatic light it can be seen an interference formation with dark and white lines spaced evenly.

1. what line is seen at the contact point A, dark or light?
2. how is the light line distance altered when the monochromatic light wavelength is altered?
3. sample thickness is increased?
4. the air is in the wedge is replaced by water (n = 1.3)?
5. intensity of the monochromatic light is increased as the wavelength remains the same?