Questions

With demand paging, a page is brought into memory only when a location on that page is actually referenced during execution. With pre-paging, pages other than the one demanded by a page fault are brought in. The selection of such pages is done based on common access patterns, especially for secondary memory devices.

Barometer is instrument which is used to measure to pressure. A slow downfall of reading suggests a low pressure area is passing in a nearby region, it may rains. If the reading is going down very fast then its an indication of storm (within 5-6 hours).

Time taken for switching from one process to other is pure over head. Because the system does no useful work while switching. So one of the solutions is to go for threading when ever possible.

The human skin is made of 3 layers. They are ::

1) The Epidermis

2) The Dermis

3) The Hypodermis

Epidermis :: 

It is the outermost layer of skin, provides a waterproof barrier and creates our skin tone.

Demis ::

It is beneath the epidermis, contains tough connective tissue, hair follicles, and sweat glands.

Hypodermis ::

It is deeper layer and is made of fat and connective tissue.