In a chemical reaction, substances (elements or compounds) called reactants are changed into other substances (compounds or elements) called products. Hence, reactants are those which start the chemical reaction.   For example: 1. In the burning of natural gas, methane (CH4) and oxygen (O2) are the reactants in the chemical reaction. are the substances formed by a chemical reaction. In the burning of natural gas, carbon dioxide (CO2) and water (H2O) are the products formed by the reaction.   2. H2+O2 ----> H2O Here H2 & O2 are called Reactants and H2O is called Product.

Answer: B) 1839 Explanation: The First Anglo-Afghan War also known as Disaster in Afghanistan was fought between British imperial India and The Emirate of Afghanistan from 1839 to 1842. A British-Indian force attacks Ghazni fort during the First Afghan War, 1839.

Answer: B) Building a Digital World Consumers can Trust Explanation: World Consumer Rights Day is being observed today (15 March 2017) which is an awareness day and theme for this year is 'Building a Digital World Consumers can trust'.

Answer: A) Acid rain Explanation: Secondary pollutants include ozone, which is formed when hydrocarbons (HC) and nitrogen oxides (NOx) combine in the presence of sunlight.   Whereas Primary pollutant are those pollutants that are directly emitted from their sources, like CO2, CO, SO2 as these gases are directly emitted form burning of fossil fuels.   Acid rain, which is formed when sulfur dioxide or nitrogen oxides react with water, sulfuric acid etc.   Hence, Acidrain is a secondary air pollutant.

Answer: C) 3 Explanation: Given two lines are parallel pa+b=2 b=-pa+2..........(1) 3a+b=4 b=-3a+4 ...........(2) m1 = -p m2= -3 The condition for the two lines to be parallel is m1=m2 p = 3

Answer: B) Bombay and Thane Explanation: India's first passenger train run took place from Mumbai to Thane for around 34 kms on 16th April in the year 1853.  That train was hauled by three steam locomotives : Sahib, Sindh and Sultan. That train had 14 carriages, carrying around 400 passengers.

Answer: A) 1 TB Explanation: 1 TB  >  1 GB  >  1 MB  >  1 KB   1 Tb (Tera Byte) = 1024 GB 1 GB (Giga Byte) = 1024 MB 1 MB (Mega Byte) = 1024 KB 1 KB (Kilo Byte) = 1024 Bytes 1 Byte = 8 Bit   Hence, largest unit of information is TB (Tera Byte) and smallest unit of information is Bit.

Answer: C) Tea Explanation: Makaibari is the world's first tea factory and was established in 1859 in Darjeeling, West Bengal.    It is most expensive tea in India which costs around 1.12 lakhs for 1 kg of tea.   Hence, Makaibari is the costliest variety of Tea.