Questions

An index is an optional structure associated with a table to have direct access to rows, which can be created to increase the performance of data retrieval. Index can be created on one or more columns of a table.

The resistivity of wire or the metal conductor is depend on the number density of free electrons in the conductor. so its mainly depends on nature of the material

Encapsulation, Object class and instance.

On 1 september 1939 German armies marched into poland. On 3 September Britain and France declared war on Germany.Thus the invasion of poland marked the beginning of the Second World War. The German armies completed the conquest of poland in less than three weeks as no aid reached poland. In spite of the declaration of war, however, there was little actual fighting for many months. Therefore, the war during the period from  september 1939 to April 1940 when germany invaded Narway and Denmark is known as the "Phoney War"

An Ice Cube is what made of water and will die if we put it in water.