General Knowledge Questions

A search engine is a information retrieval program that constantly collects information on the Web, following links in Web sites and reading Web pages. The search results are presented in a list format and are called as hits.

A metasearch engine is a search tool that uses another search engine's data to produce its own results from the Internet. These engines take input from a user and simultaneously send out queries to third party search engines for results. It searches other search engines rather than individual Web sites.

Examples of Metasearch engine includes - Dogpile, Zoo, Yabado, Metager, etc...

p type of semiconductor is obtained when Silicon is doped with a trivalent impurity like Aluminium. Aluminium is a p-type dopant, which means that when a semiconductor i.e. silicon is doped with aluminium, it creates a hole (positively charged carrier) by accepting an electron from the silicon atom. Electrical conductivity of semiconductors increasesand resistivity remains the same

The size of gear is usually specified by pitch circle diameter.

An autoimmune disease is a condition in which your immune system mistakenly attacks your body.

The immune system normally guards against germs like bacteria and viruses. When it senses these foreign invaders, it sends out an army of fighter cells to attack them. Normally, the immune system can tell the difference between foreign cells and your own cells.

In an autoimmune disease, the immune system mistakes part of your body — like your joints or skin — as foreign. It releases proteins called autoantibodies that attack healthy cells. Some autoimmune diseases target only one organ. Type 1 diabetes damages the pancreas. Other diseases, like lupus, affect the whole body.

Hence, Systematic lupus erythematosus is an autoimmune disease that affects multiple organs.

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