Questions

Black soils are rich in montmorillonitic and beidellitic group of clay minerals and are poor in nitrogen, phosphorus and organic matter. Black soils are most suitable for the cotton crop hence it is also known as black cotton soil. Besides cotton, the soil is suitable for the cultivation of crops like wheat, groundnut, chillies, tobacco and jowar.

Magnetism in materials is due to circular motion of electrons.

The credit of inventing the television goes to Philo Farnsworth. Electronic television was first successfully demonstrated in San Francisco on Sept. 7, 1927.

Abraham Lincolon was an American statesman and lawyer who served as the 16th President of the United States from March 1861 until his assassination in April 1865.

Lincoln led the United States through the American Civil War—its bloodiest war and perhaps its greatest moral, constitutional, and political crisis.