Answer: Alfred Wegener provided some of the important points that supported the theory of continental drift. They are as follows-
- The continents were once all attached together, and this can be proved by studying the coastlines of some of the continents that perfectly matches with one another.
- The appearance of similar rock types and similar fossils (including both animals and plants) has also contributed much information that continents were once all together.
Answer:
4/3
Explanation:
Shown in the picture attached
Answer:
Angle of first order maximum, 
Explanation:
Given that,
Wavelength of the light, 
Number of lines, N = 8000 per cm
The relation between the number of lines and the slit width is given by :


The equation of grating is given by :

n = 1



So, the angle of the first-order maximum is 21.19 degrees. Hence, this is the required solution.