Question Discussion & Solution

The correct answer is Calcium Carbonate.

Key Points

• The chief component of the nacre that constitutes the pearl is aragonite (CaCO₃).
• Nacre also contains a small amount of conchiolin, a hornlike organic substance (albuminoid) that is the main constituent of the mollusc's outer shell.
• Pearl also contains Magnesium Carbonate(MgCO₃) along with Calcium Carbonate.

Additional Information

• Calcium carbonate is a common substance found in rocks as the minerals calcite and aragonite and is the main component of eggshells, snail shells, seashells, and pearls. 
• The Molar Mass of Calcium Carbonate is 100.0869 g/mol.
• Melting point: 825 °C.

The correct answer is Rajasthan.

Key Points

• 'Ghaggar and Banas' are rivers that feed the state of Rajasthan.
• The Ghaggar is an intermittent river in India, flowing during the monsoon rains.
  • It originates in the village of Dagshai in the Shivalik Hills of Himachal Pradesh at an elevation of 1,927 meters (6,322 ft) above mean sea level and flows through Punjab and Haryana states into Rajasthan.
  • The main tributaries of the Ghaggar are the Kaushalya river, Markanda, Sarsuti, Tangri and Chautang.
• Banas River :
  • The Banas is a river that lies entirely within the state of Rajasthan in western India.
  • It is a tributary of the Chambal River, itself a tributary of the Yamuna, which in turn merges into the Ganga.
  • It flows northeast through the Mewar region of Rajasthan, then across Hadavati before meeting the Chambal near the village of Rameshwar in Sawai Madhopur District.

Crane, swan and falcon are the birds whereas frog is not a bird.

Option 3 is correct, i.e. p-block.

• Modern Periodic Table:
  • The Modern Periodic Table is classified into the following elements - p-block, s-block, d-block, and f-block.
  • The p-block elements include chalcogens, pnictogens, halogens, inert gases.
    • The 18^th group is known as Inert gas, zero groups, Nonreactive gases.
    • The 17^th group is known as Halogen.
    • The 16^th group is known as Chalcogen.
    • The 15^th group known as Pnictogen.
    • Pnictogen group refers to the choking property of nitrogen gas (as opposed to air, which contains oxygen as well as nitrogen).
    • Nitrogen family elements consist of atoms having 5 electrons in their outer energy level. Two of the electrons are in the s subshell, with 3 unpaired electrons in the ​p subshell.
  • The s-block elements include alkali metals and alkaline earth metals. 
  • The d-block elements include Transition elements.
  • The f-block elements include Inner Transition Elements.

The correct answer is In 1960.

• In 1960, the 'State Assessment Organization' was established in Rajasthan.

Key Points

• The State Evaluation Organisation was set up in the State on 1^st April 1960.
• It was set up with the objective of undertaking evaluation of Panchayati Raj and Community Development Programme, and further assigned the task of making an evaluation of development schemes/ projects initiated under different Five Year Plans.
• Presently it is working as an integral part of the State Planning Machinery and conduct the evaluation studies on various subjects, schemes, projects and programmers as required by the State Government as well as by the Central Government.