CBSE Class 9 Social Science Chapter 03 Atmosphere And Climate MCQs Set 03

Answer: (B) The height of a location above mean sea level

Explanation:
Altitude is explained as the height of a location above mean sea level, with sea level itself treated as the zero point for measurement.

Answer: (A) Around 12 kilometres

Explanation:
The troposphere, home to nearly all weather activity, has an average height of about 12 kilometres before giving way to the tropopause and then the stratosphere.

Answer: (A) Argon

Explanation:
Argon accounts for about 0.93 per cent of the atmosphere, making it a much smaller share than nitrogen or oxygen but still more prominent than the other trace gases mentioned.

Answer: (C) The thermosphere

Explanation:
The ionosphere sits within the thermosphere, the layer where rapidly rising temperatures and radio-wave reflection are described together in the chapter.

Answer: (B) Because the Moon appears to occupy a different one of the sky's 27 fixed divisions each night

Explanation:
The sky is divided into 27 equal sections along the Moon's path, and since the Moon takes about 27 days to circle the Earth relative to the stars, it moves into a new section, or 'mansion', almost every day.

Answer: (B) Tracking the positions of the Moon and the Sun in the sky

Explanation:
The chapter credits Kṛiṣhiparāśhara with a rainfall-prediction technique built around watching how the Moon and Sun were positioned, distinct from Varāhamihira's nakshatra-based approach in the Bṛihatsaṁhitā.

Answer: (B) The Satluj, Beas, and Ravi

Explanation:
Heavy monsoon rain, worsened by western disturbances, caused the Satluj, Beas, and Ravi to swell and flood large parts of the state, alongside the already-rising Ghaggar.

Answer: (B) Poultry and dairy farms were damaged, and many animals fell sick or died

Explanation:
The chapter lists damaged poultry and dairy farms among the flood's consequences, noting that cows, buffaloes, and chickens either fell ill or died as a result.

Answer: (A) Melting glaciers and rising sea levels

Explanation:
As greenhouse gases trap more heat and raise global temperatures, the chapter notes that glaciers melt and sea levels rise, alongside more frequent floods, droughts, and biodiversity loss.

Answer: (B) To help students reflect on daily habits and identify changes that lower their environmental impact

Explanation:
By scoring choices around transport, electricity, water, and waste, the activity nudges students to notice which everyday habits add to their carbon footprint and commit to small, practical improvements.

Answer: (B) Between the Tropic of Cancer and the Tropic of Capricorn

Explanation:
The Torrid Zone straddles the equator, stretching between the Tropic of Cancer in the north and the Tropic of Capricorn in the south, where sunlight strikes most directly.

Answer: (B) To improve monsoon prediction for India across all time frames

Explanation:
The mission's purpose is described plainly: to strengthen India's ability to forecast the monsoon over every time scale, using advanced weather and climate models developed by the Ministry of Earth Sciences.

Answer: (B) The movement of air from a high-pressure area to a low-pressure area

Explanation:
Wind is simply air in motion, flowing from zones of higher pressure toward zones of lower pressure, and its strength can range from a gentle stir to a destructive storm.

Answer: (B) A light breeze can be felt on the face and rustles leaves, while a strong breeze sways large branches and makes umbrellas hard to use

Explanation:
The table's effects scale up with speed: a light breeze is mild enough to feel on the skin and rustle leaves, whereas a strong breeze is powerful enough to sway thick branches and make handling an umbrella difficult.

Answer: (B) To show that heavy rainfall alone cannot fully explain the scale of damage, since weak embankments, riverside construction, and delayed warnings also contributed

Explanation:
The case study separates the two categories deliberately, showing that while intense monsoon rain and swollen rivers set the stage, factors like ageing embankments, encroachment near riverbanks, silted channels, and late warnings turned a natural event into a much larger disaster.

Answer: (A) The Roman goddess of dawn

Explanation:
Aurora was the Roman goddess of dawn, and the shimmering polar lights were named after her because of their glowing, dawn-like colours in the sky.

Answer: (B) 80 to 700 km

Explanation:
The thermosphere lies above the mesopause and stretches from 80 km up to about 700 km, a region where temperature rises sharply because gas molecules absorb X-rays and short-wave ultraviolet radiation from the Sun.

Answer: (B) Accumulation of silt and mud reducing the water-carrying capacity of rivers and dams

Explanation:
Over time, silt and mud had built up in rivers and dams, shrinking their capacity to hold and channel water, which added to the destruction caused by the heavy rains that year.

Answer: (B) A force of attraction between objects with mass, which holds the atmosphere close to the Earth's surface

Explanation:
Gravity is described as the pull of attraction between massive bodies like the Earth and the Sun, and it is specifically this force that keeps the blanket of atmospheric gases wrapped around our planet instead of drifting into space.

Answer: (C) Vasanta

Explanation:
Vasanta, corresponding roughly to March-April, is listed as the opening season in the traditional six-season Ritu cycle before Grishma, Varsha, Sharad, Hemanta, and Shishira follow in order.

Answer: (B) Tropical monsoon climate

Explanation:
India's weather patterns are shaped heavily by seasonal wind reversals, so the chapter broadly labels the country's climate as tropical monsoon, with the IMD further splitting the year into four seasons.

Answer: (D) 4 points

Explanation:
The scoring scale runs from low (1 point) up to very high impact choices, which carry the heaviest weight of 4 points, reflecting habits like taking frequent flights that add the most to one's carbon footprint.

Answer: (A) What is the mechanism of monsoon?

Explanation:
One of the four guiding questions opening the chapter directly asks about how the monsoon mechanism works, setting up the later detailed discussion of south-west and north-east monsoon winds.

Answer: (B) They relied on wind direction for sailing and noticed its seasonal reversal

Explanation:
Since these sailors depended entirely on the wind to move their ships, the seasonal flip in wind direction was something they could not help but notice and take advantage of during their voyages, which is why the Arabs later named this reversal 'mausim'.

Answer: (A) Rainwater that falls as precipitation

Explanation:
Precipitation, especially rain, is described as the main way water enters the ground and replenishes groundwater stores, making rainfall central to a region's water supply.