Contemporary India - I

On 21st June, the Sun is directly over the Tropic of Cancer. Geometrically, it means the Sun is normal (90°) to the Tropic of Cancer and makes an angle of 47° to the Arctic Circle. As such, the Sun is above the horizon for all areas north of the Arctic Circle. The entire area in the Arctic Circle experiences day. The North Pole is inclined towards the sun and the places beyond the Arctic Circle experience continuous daylight for about six months. Since a large portion of the Northern Hemisphere is getting light from the sun, it is summer in the regions north of the equator. The longest day and the shortest night at these places occur on 21st June.

At this time in the Southern Hemisphere, all these conditions are reversed. It is winter season there. The nights are longer than the days. This position of the earth is called the Summer Solstice.

Source Attribution:

• GC Leong
• NCERT: Fundamentals of Physical Geography

Alfalfa, also called lucerne, is a perennial flowering plant in the legume family Fabaceae. It is cultivated as an important forage crop in many countries around the world. Symbiotic N₂ fixation by alfalfa provides substantial amounts of nitrogen (N) to livestock operations, subsequent crops, and soil organic matter. Hence option 1 is correct.

Amarnath: Amaranthus is a cosmopolitan genus of annual or short-lived perennial plants collectively known as amaranths. Hence option 2 is not correct.

Chickpea: The chickpea or chick pea is an annual legume of the family Fabaceae. Hence option 3 is correct.

Clover: Nitrogen is "fixed" in clovers through a symbiotic relationship with Rhizobium bacteria that infects the plant's roots. Hence option 4 is correct.

Purslane: Purslane is a green, leafy vegetable that can be eaten raw or cooked. It is known scientifically as Portulaca oleracea, and is also called pigweed, little hogweed, fatweed and pusley. This succulent plant contains about 93% water. It has red stems and small, green leaves. Hence option 5 is not correct.

Spinach: Spinach is a leafy green flowering plant native to central and western Asia. It is of the order Caryophyllales, family Amaranthaceae. Hence option 6 is not correct.

Source Citation: NCERT

The Godavari River has several principal tributaries, including the Penganga, Indravati, Pranahita, and Manjra. Among the rivers listed in the question, Indravati and Pranahita are tributaries of the Godavari. Therefore, the correct answer is option (d) 2 and 3 only.

Source: NCERT: Class 12 India Physical Environment

Feeding on sea grass, dugongs are found in sea grass beds, sheltered waters, lagoons and bays. Fourteen sea grass species are found in the marine waters in the country of which 13 are found in the Gulf of Mannar and Palk Bay areas.

Dugongs had been brought under Schedule I of the Wildlife Protection Act; the punishment for its poaching is imprisonment.

Source Attribution: NCERT: India Physical Environment Std XI

Montreal Protocol on Substances that Deplete the Ozone Layer (a protocol to the Vienna Convention for the Protection of the Ozone Layer) is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion.

Source: NCERT