Questions

Electronic Flash differs from the consumable bulb flash in important aspects. Instead of creating light by burning up in an atmosphere containing oxygen, a consumable material (each bulb being used therefore only once), it produces a brilliant incandescent by discharging a current for a brief instant through a rarified gas, usually xenon. The gas glows every time the discharge is made through it but it is not consumed, so that many thousands of flashes are obtainable from a single tube, which helps to offset the much higher cost of the initial apparatus.

The followers of Islam religion is called Muslims.

According to Muslims, God sent prophets to mankind to teach them how to live according to His law. Muhammad is believed by Muslims to be the last prophet sent by God (Allah). The Muslim holy book is called the Quran.

In all the given options, molecules are containing nonpolar covalent bonds.

Permanent hardness of water may be removed by the addition of Sodium Carbonate.

A primary key is a special relational database table column or combination of columns designated to uniquely identify all table records. That is, A primary key is a column or set of columns in a table that uniquely identifies tuples (rows) in that table.

A primary key, also called a Primary Keyword.

Main Features Primary key are ::

It must contain a unique value for each row of data.

It cannot contain null values.