Questions

Passivity of iron is due to formation of an extremely thin and impervious film of ferrosoferric oxide Fe3O4on the surface of iron. Chromic acid, being a powerful oxidising agent (like nitric acid ) renders iron passive. 

The water rise in a capillary tube dipped in water is such that the weight of water in the tube above the surface of water in the vessel is equal to (balances) the upward force due to surface tension. So it is clear that if the the bore (radius) to the tube is decreased, the height of the water column in it must be greater.  So, (a) is correct.

Indian international cricketer Virat Kohli has named as the 'Captain of the Year' at the 10th annual ESPNcricinfo Awards. Kohli led India to nine wins out of 12 Tests in the year 2016.

♦ The ESPNcricinfo awards honour the best batting and bowling performances across the international formats of the game in the preceding calendar year.
♦ This year ESPNcricinfo introduced awards for women’s cricket across all three international formats.

When the European union formed nations began to cooperate on law enforcement. The European Union is set up with the aim of ending the frequent and bloody wars between neighbours, which culminated in the Second World War.

As of 1950, the European Coal and Steel Community begins to unite European countries economically and politically in order to secure lasting peace. The six founding countries are Belgium, France, Germany, Italy, Luxembourg and the Netherlands. The 1950s are dominated by a cold war between east and west.

The historical roots of the European Union lie in the Second World War. Europeans are determined to prevent such killing and destruction from ever happening again.