Question Discussion & Solution

Eagle, Bird, Crocodile

All Eagle is the Bird and Crocodile is the reptile. 

So,  Venn diagram given bellow-

Hence, option 4 is the correct answer.

Biosphere reserves are areas of terrestrial and coastal ecosystems that promote the conservation of biodiversity with its sustainable use. 

• They are internationally recognized within the framework of UNESCO’s Man and Biosphere (MAB) program and nominated by national governments.
• There are over 500 biosphere reserves in over 100 countries around the world.
• There are 18 notified Biosphere reserves in India.
• Out of them, 11 Biosphere Reserves are in UNESCO’s MAB World Network. 

Important Points

Biosphere Reserves and their respective years of including in the MAB network are as follows:

• ​Nilgiri (2000)
• Gulf of Mannar (2001)
• Sunderban (2001)
• Nanda Devi(2004)
• Nokrek (2009)
• Pachmarhi(2009)
• Similipal (2009)
• Achanakmar-Amarkantak Biosphere Reserve (2012)
• Great Nicobar Biosphere Reserve (2013)
• Agasthyamala Biosphere Reserve (2016)
• Khangchendzonga Biosphere Reserve(2018)

From the above, we can conclude that Nilgiri Biosphere Reserve is the first Biosphere reserve in India.

Additional Information​ 

Nilgiri Biosphere reserve:-

• ​The Nilgiri Biosphere Reserve was the first and Oldest biosphere reserve in India established in the year 1986.
• It is located in the Western Ghats and includes 2 of the 10 biogeographical provinces of India.
• The Nilgiri Biosphere Reserve falls under the biogeographic region of the Malabar rain forest.
• The Mudumalai Wildlife Sanctuary, Wayanad Wildlife Sanctuary Bandipur National Park, Nagarhole National Park, Mukurthi National Park, and Silent Valley are the protected areas present within this reserve.

The correct answer is In 1982.

• The National Bank for Agriculture and Rural Development (NABARD) is a top-level development financial institution in India, established in 1982 to provide agricultural and rural credit.

Key Points

• National Bank for Agriculture and Rural Development (NABARD) is the apex institution of Rural Credit.
• It was established on 12 July 1982 by the merger of Agriculture Credit Department and reconstruction of Agriculture and Development Corporation of the Reserve Bank of India.
• Its establishment is based on the recommendations of Shivraman Committee.
• Food stocks are maintained by the Central Government for three purposes:
  • Maintaining prescribed buffer stock norms for food security,
  • Monthly supply through Public Distribution System (PDS),
  • Market intervention to stabilise open market prices.

CONCEPT:

• Ultrasonic waves are the sound waves with frequencies higher than the upper audible limit of human hearing.
  • They have a short wavelength.
• Echo: If we shout or clap near a suitable reflecting object such as a tall building or a mountain, we will hear the same sound again a little later. This sound which we hear is called an echo.
  • Echoes are heard due to the phenomenon of Reflection of sound waves.
• SONAR: It a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, communicate with or detect objects on or under the surface of the water
  • SONAR stands for ‘Sound Navigation and Ranging.’
  • SONAR is based on the principle of echo.
  • Sonar is often used as a measurement of acoustic location and echo characteristics of the target object in the water.
  • It sends ultrasonic waves towards the bottom area of the sea and after reflection, the sound comes to the ship. We measure the time taken by the sound wave and then we get the depth. 

EXPLANATION:​

• From the above discussion, we can say that the SONAR uses the principle of reflection of sound waves(Echo) to detect and locate objects. So option 2 is correct.
• Reverberation: The persistence of sound in a closed enclosure, due to continuous reflections at the walls or the floor or the ceiling of the enclosure, even after the source has stopped producing sound is known as 'reverberation'.

The least possible Venn diagram is,

Conclusion 1: All apples are bananas → True (This is definitely true)

Conclusion 2: Some bananas are mangoes → True (This is definitely true)

Hence, both 1 and 2 follow.