You have not provided the diagram, therefore, I cannot provide an exact answer.
However, I will try to help by explaining how to solve this problem.
When light moves from air to glass:1- part of the light is reflected back into the air where the angle of incidence is equal to the angle of reflection
2- part of the light enters the water and refracts. The angle of refraction can be calculated using Snell's law.
In a diagram, the reflected ray would be the one getting back into air while the refracted ray would be the one entering the water.
You can check the attached diagram for further illustrations.
Hope this helps :)
Answer:
The width of the central bright fringe on the screen is observed to be unchanged is 
Explanation:
To solve the problem it is necessary to apply the concepts related to interference from two sources. Destructive interference produces the dark fringes. Dark fringes in the diffraction pattern of a single slit are found at angles θ for which

Where,
w = width
wavelength
m is an integer, m = 1, 2, 3...
We here know that as
as w are constant, then

We need to find
, then

Replacing with our values:


Therefore the width of the central bright fringe on the screen is observed to be unchanged is 
Resistance reduces the current. If there is more resistance, there is less current.
It defines that if two thermodynamic systems are each in equilibrium with a third system, then they are in equilibrium with each other.
Answer:
The correct answer to the following question will be "41.87 m".
Explanation:
The given values are:
The speed of trooper = 
The velocity of red car = 
Now,
A red car goes as far as possible until the speed or velocity of the troops is the same as that of of the red car at
(∵
)

then,
The distance covered by trooper,


The distance covered by red car,
= 
= 
Maximum distance = 
=