Two closely located monochromatic light sources create a fixed interference pattern on a screen.  The frequency of one of the sources is then decreased.   What will happen to the interference pattern as a result?   a. the fringe spacing will decrease b. the fringe spacing will increase c. the pattern will completely disappear d. the fringes will shift left or right, but the spacing will remain constant

confused on these two questions

The headlights of a car are 1.5 m apart. Your pupil has a diameter of 5 mm, and the wavelength of the light from the headlights is 600 nm. a. If the car is 50 m away from you, what is the angle between the headlights? b. Can you tell whether the car has two headlights or one?  c. What is the maximum distance at which you would still be able to resolve headlights? d. The pupil of your eye changes size depending on how much light it is exposed to. If the diameter of your pupil increased from 5 mm to 7 mm, would your answer in part (c) get larger or smaller?

What is the highest order bright fringe that will be observed when green light of wavelength 550 nm is incident on a Young's double slit apparatus with a slit spacing of 11 µm? a. m = 12   b. m = 16   c. m = 18   d. m = 20   e. m = 14

When polychromatic visible light shines through a diffraction grating, the colors seen closest to the central maximum will: A. be visible as the lowest wavelength in the mixture B. be visible as the highest wavelength in the mixture C. be a mixture of the wavelengths present D. Always be white