Questions

A binary semaphore is one, which takes only 0 and 1 as values. They are used to implement mutual exclusion and synchronize concurrent processes.

26 + 26 + 26 = 78

No. of  sweets each student get = 20% of 65 = 13

No. of sweets each teacher get = 40% of 65 = 26

No. of sweets distributed to 65 students =  13 × 65 = 845

No. of sweets distributed to 4 teachers = 4 × 26 = 104

Therefore, the total no. of sweets there = 845 + 104 = 949.

A Mirage is a naturally occurring optical phenomenon in which light rays bend to produce a displaced image of distant objects or the sky.

• It is caused due to Total internal Reflection.

• It is an optical illusion observed in deserts or hot summer days due to which a person sees a pond of water some distance ahead of him in which the surrounding objects appear inverted.

How Mirage Forms::

1. The temperature of other layers of atmosphere goes on decreasing as we go up.
2. Therefore density and refractive index of air changes as one goes up.
3. Thus a ray of light,gets refracted more and more away from the normal.
4. At a particular angle when a ray of light exceeds critical angle, total internal reflection takes place and ray of light gets reflected in the same medium.
5. when the reflected ray reaches our eye, it appears as coming from tree or sky .
6. Hence the inverted image of tree creates an impression from a pond of water.