Final answer:
In a multi-slit interference pattern with eight slits illuminated by monochromatic light, the intensity of the first secondary maxima compared to the principal maxima is 1/8. This highlights how the principal maxima are significantly brighter than the secondary maxima. Therefore, the correct answer is b. 1/8.
Step-by-step explanation:
The question concerns the intensity of secondary maxima compared to the intensity of principal maxima in a multi-slit interference scenario, specifically with eight slits and monochromatic light.
The intensity of secondary maxima in a multiple-slit interference pattern can be determined using the interference function sin^2(Nβ/2) / N^2sin^2(β/2), where N is the number of slits, and β is the phase difference between waves from adjacent slits.
In this case for the eight-slit system, the intensity ratio of the first secondary maxima to principal maxima turns out to be 1/8.
This intensity ratio signifies that the principal maxima are much more intense compared to the secondary maxima, as is typical in multiple-slit interference patterns.