The average salinity of sea water is 3.5% or 35 parts per thousand. In other words, for every 1 litre of sea water there is 35 grams of dissolved salts (NaCl) .

A flexible tube called an endoscope is used to view different parts of the digestive tract. When passed through the mouth (as shown on the left), an endoscope can be used to examine the esophagus, stomach, and some of the small intestine.

Acetylene is the only fuel gas suitable for gas welding because of its favourable flame characteristics of both high temperature and high propagation rates. Other fuel gases, such as propane, propylene or natural gas, produce insufficient heat input for welding but are used for cutting, torch brazing and soldering.

Lakshadweep was formerly known as Laccadive, Minicoy and Aminidivi Islands.

Currently, there are 29 states and 7 union territories in India.

There are seven union territories in India. These are Delhi, Puducherry, Chandigarh, Dadra and Nagar Haveli, Andaman and Nicobar Islands, Daman and Diu and Lakshadweep.

The Constitution of India establishes a federal system of government. It contains all the usual features of a federation Viz., two government, Division of powers, written constitution, Supremacy of constitution, Independent judiciary and Bicameralism. Article 1 says that India is a union of states which implies two things: first, Indian federation is not the result of an agreement by the states and second, No state has the right to secede from the federation.