In 1815 the European powers of Britain, Russia, prussia and Austria had collectively defeated Napoleon. Their chief representatives met at Vienna to come to a settlement for Europe. The Congress was hosted by Austrian chancellor Duke Metternich. The delegates grew up the Treaty of Vienna in 1815 with the aim of  undoing what Napoleon had transferred in Europe.

1.The Bourbon dynasty was restored to power in France. They were deposed during the French Revolution. France lost its territories which had been annexed under Napoleon.

2. A series of states were carved out on the French frontiers to prevent French expansion in the coming future. Thus , the kingdom of Netherlands which included Belgium was set up in the north and Genoa was added to Piedmont in the south.

Prussia was given new territories on its Western Frontiers while Austria was given control of Northern Italy. The German confederation of 39 States was left and it is.

4. In the east, Russia was given a part of Poland why Prussia was given a portion of Saxony. The main aim was to restore the monarchies  that were overthrown by Napoleon and re-establish the authority of Conservatives in Europe.

1. In 1845, weaver in Silesia had led a Revolt against contractors who supplied them with raw materials and got finished goods.

2.A crow of weavers marched in pairs up to the mansion of their contractors demanding higher wages.

3. They smashed there window panes and also plundered the supply of cloth. As a result, the contractors fled away from their houses with their families.

Culture played an important role in creating the idea of 'nation in Europe:

1. Romanticism was a cultural movement that believed in emotions, intuitions and mystical feelings over reason and science. They tried to evoke the feelings of a common past and shared heritage.

2. Romantics like Johann Gottfried Herder believed that German culture was alive among the common people- das Volk. The idea of nation was popularised through the folk culture of songs, poetry, and dance.

3. Local culture was sought also to reach the large population of illiterate people. In Poland, Karol Kurpinski turned the folk dances and music into nationalist symbols.

4. The language was also essential as a nationalist identity. When Polish was forcefully removed from schools and Russian was imposed everywhere after Russian occupation, the people saw the use of Polish language as a sign of national resistance.

Electric Motor:

An electric motor is a rotating device that converts electrical energy to mechanical energy. Electric motor is used as an important component in electric fans, refrigerators, mixers, washing machines, computers, MP3 players etc. An electric motor consists of a rectangular coil ABCD of insulated copper wire. The coil is placed between the two poles of a magnetic field such that the arm AB and CD are perpendicular to the direction of the magnetic field. The ends of the coil are connected to the two halves P and Q of a split ring. The inner sides of these halves are insulated and attached to an axle. The external conducting edges of P and Q touch two conducting stationary brushes X and Y, respectively. Current in the coil ABCD enters from the source battery through conducting brush X and flows back to the battery through brush Y. Notice that the current in arm AB of the coil flows from A to B. In arm CD it flows from C to D, that is, opposite to the direction of current through arm AB. On applying Fleming’s left hand rule for the direction of force on a current-carrying conductor in a magnetic field. The force acting on arm AB pushes it downwards while the force acting on arm CD pushes it upwards. Thus the coil and the axle O, mounted free to turn about an axis, rotate anti-clockwise. At half rotation, Q makes contact with the brush X and P with brush Y. Therefore the current in the coil gets reversed and flows along the path DCBA. A device that reverses the direction of flow of current through a circuit is called a commutator. In electric motors, the split ring acts as a commutator. The reversal of current also reverses the direction of force acting on the two arms AB and CD. Thus the arm AB of the coil that was earlier pushed down is now pushed up and the arm CD previously pushed up is now pushed down. Therefore the coil and the axle rotate half a turn more in the same direction. The reversing of the current is repeated at each half rotation, giving rise to a continuous rotation of the coil and to the axle.

The commercial use of motor:

1. 1. 1. An electromagnet in place of permanent magnet.
      2. Large number of turns of the conducting wire in the current-carrying coil.
      3. A soft iron core on which the coil is wound.

The soft iron core, on which the coil is wound, plus the coils, is called an armature.

The difference between a tiger in a zoo and in a forest is huge as in the former it is a caged animal who has lost its freedom whilst in the latter it is independent and supreme.
The tiger is the king of the forest. It is born free. It roams about the forest roaring regally. It enjoys its supremacy as all animals are afraid of it. It is thus wildly royal. In the zoo however, it is a trapped animal. It is like a king in fetters, a king without a kingdom. It can no longer enjoy hunting. It is more like a circus clown-a sheer spectacle.
It is bound by the rules and regulations of the zoo-keeper. Lost is its suzerainty and dignity. It is just a puppet-king.

An electric cell is a device, which converts chemical energy into electrical energy. It has two terminals, which are made up of metal: one terminal is positive, while the other one is negative. When the two terminals are connected to an electrical device, electric current flows through it.

• Strong acids completely dissociate into their ions in water, while weak acids only partially dissociate.
• There are only a few (7) strong acids, so many people choose to memorize them. All the other acids are weak.
• The strong acids are hydrochloric acid, nitric acid, sulfuric acid, hydrobromic acid, hydroiodic acid, perchloric acid, and chloric acid.
• The only weak acid formed by the reaction between hydrogen and a halogen is hydrofluoric acid (HF). While technically a weak acid, hydrofluoric acid is extremely powerful and highly corrosive.

In 1815, the representatives of the European powers - Britain, Russia,Prussia and Austria wanted to establish long-lasting peace and stability after they defeated Napolean.

Thus, they drew up the Treaty of Vienna of 1815 with the intenstion of undoing most of the changes brought about during the Napoleonic wars and creating a new conservative order in Europe.

• The Bourbon dynasty was brought back to power and France lost the territories it had annexed under Napoleon.  
• To prevent the French evasion, a series of states werre set up on the boundaries of France.
• This lead to the setting up of kingdom of the Netherlands (inclusive of Belgium) in the north and the kingdom of Genoa (added to Piedmont) in the south.
• Prussia was given important new territories on its western frontiers, while Austria was given control of northern Italy.
• However, Napolean's German confederation of 39 states was left untouched.
• In the east, Russia was given part of Poland while Prussia was given a portion of Saxony.