CBSE Class 7 Social Science Chapter 02 Understanding The Weather MCQs Set 03

Answer: (A) Changes in the surrounding humidity

Explanation:
Pine cones close up when the air is humid to shield their seeds, and open again once the air turns dry, letting the seeds scatter in favourable conditions.

Answer: (A) Dry conditions allow the seeds to spread more effectively and survive

Explanation:
Releasing seeds only when it is dry gives them a better chance of dispersing widely and establishing themselves, rather than being lost in wet conditions.

Answer: (A) Collecting funnel, measuring tube and measuring scale

Explanation:
• Rainwater first enters through the collecting funnel
• It then drops down into the measuring tube below
• The attached measuring scale is read to note the depth of water collected

Answer: (A) Water existing as a gas rather than as a liquid

Explanation:
Water vapour simply means water that has taken a gaseous form instead of remaining liquid, and it is this vapour whose amount in the air determines humidity.

Answer: (A) Controlling moisture in the air matters for their processes and for keeping items well preserved

Explanation:
Museums need a dry environment to stop their exhibits from getting damaged, while food processing depends on precise moisture control, which is why both keep a hygrometer handy.

Answer: (A) Clinical thermometer and laboratory thermometer

Explanation:
This is a 'Let's Remember' callback to the earlier science lesson, not new content — it simply recalls the clinical and laboratory thermometers students had already studied.

Answer: (A) The sun produces rain, rain produces food, and food gives rise to living beings

Explanation:
• The motto begins with the sun causing rain
• Rain, in turn, is said to bring about food
• And food is described as the origin of living beings

Answer: (A) To gather several instruments in one place so readings can be taken regularly and tracked over time

Explanation:
A weather station is essentially a hub bringing thermometers, rain gauges, barometers and other tools together, making it far easier to record data at fixed intervals for forecasting.

Answer: (A) Its three or four cups spin faster on a vertical shaft as the wind gets stronger

Explanation:
The cups catch the moving air and spin around a shaft, and a meter simply counts these rotations over time to work out the wind speed in km/h.

Answer: (A) Wind strongly affects how safely and smoothly planes fly or boats sail

Explanation:
Since wind speed and direction directly influence flying and sailing conditions, both pilots and sailors need this data to plan their journeys safely.

Answer: (A) Navigation and environmental monitoring

Explanation:
The text lists navigation and environmental monitoring alongside agriculture and aviation as areas that benefit from the accurate, round-the-clock data an AWS provides.

Answer: (A) To let the body gradually adjust to a new climate or condition

Explanation:
Travellers pause on their way up so their bodies can slowly get used to the thinner air and lower oxygen levels found at high altitudes, rather than facing sudden strain.

Answer: (A) The soil dries out more quickly

Explanation:
Stronger winds speed up evaporation from the ground, which is why farmers watch wind conditions closely when deciding how to manage their fields.

Answer: (A) Temperature, wind, pressure and location

Explanation:
Humidity does not depend on water vapour alone — the chapter notes that temperature, wind, atmospheric pressure and even where a place is located all play a part.

Answer: (A) An alert, meaning people should be prepared

Explanation:
The colour code moves from green (no warning) through yellow (watch) and orange (alert, be prepared) up to red (warning, take action), so orange sits one step below the most severe level.

Answer: (A) Studies weather data scientifically to forecast future conditions

Explanation:
Meteorologists gather readings from instruments over long stretches of time and apply scientific methods to predict how the weather will unfold in the coming hours, days or weeks.

Answer: (A) The air becomes thinner, so there is less weight of air pressing down

Explanation:
Higher up, there is simply less air above pressing down, which is why the air feels thinner and pressure readings fall — this is also why climbers can feel breathless or dizzy.

Answer: (C) Atmospheric pressure

Explanation:
The section moves through temperature, precipitation, atmospheric pressure, wind and finally humidity — pressure comes third, directly after the discussion of rain gauges.

Answer: (A) No warning has been issued for that area

Explanation:
Green sits at the calmest end of the colour scale used on the map, showing that no unusual weather event is expected there — quite different from the red 'take action' warning used for the most severe conditions.

Answer: (C) Be updated, as conditions may change

Explanation:
Yellow corresponds to a 'watch' status on the scale — it's a milder alert than orange or red, simply asking people to keep track of updates rather than act right away.

Answer: (D) Gulmarg

Explanation:
Gulmarg's actual maximum was recorded at –2.6°C, well below every other station listed in the table, including Pahalgam's 1.1°C.

Answer: (D) Gulmarg

Explanation:
The 24-hour snowfall column shows Gulmarg at 35.0 cm, ahead of Pahalgam's 23.0 cm and Kukernag's 30.0 cm.

Answer: (A) Rainy-day air already holds a lot of water vapour, leaving little room for more to evaporate

Explanation:
Because humidity is already high during rain, the surrounding air is closer to being saturated with water vapour, so liquid water has less opportunity to turn into vapour and evaporation slows down.

Answer: (B) Open ground on an elevated platform, away from anything blocking the rain

Explanation:
The chapter's instructions call for an open, flat spot that will not tilt in the wind and is clear of obstructions that could stop rain from falling straight into the funnel — a raised open platform fits this best, unlike a sheltered verandah or a narrow wall.

Answer: (B) How the five elements of weather are measured with instruments and used to forecast conditions

Explanation:
• The chapter opens by naming temperature, precipitation, pressure, wind and humidity as the elements of weather
• It then introduces the specific tool used to measure each one, from thermometers to hygrometers
• Finally it connects these measurements to forecasting, showing how predictions help people prepare for storms, heat waves and other extreme events