Free Environment and Atmosphere MCQs with Answers

291. A wind which reverses seasonally is known as_____?

• A. Trade
• B. Cyclonic
• C. Monsoon
• D. Polar

Explanation: A monsoon is a seasonal wind system that reverses direction because land and sea heat and cool at different rates. Trade and polar winds do not undergo this regular seasonal reversal.

292. The Stevenson screen contains all of these EXCEPT:

• A. Wet bulb thermometer
• B. Maximum thermometer
• C. Ordinary thermometer
• D. Anemometer

Explanation: A Stevenson screen houses thermometers, including ordinary, maximum, and wet-bulb instruments, while shielding them from direct sunlight. An anemometer measures wind speed and is installed separately in an exposed position.

293. Weather describe the condition of ______ at any one time.

• A. The earth
• B. The land surface
• C. The atmosphere
• D. The ionosphere

Explanation: Weather describes the short-term condition of the atmosphere, including temperature, pressure, wind, humidity, and precipitation. Climate, by contrast, describes long-term patterns.

294. Water vapour turns into clouds in the atmosphere when:

• A. It rains
• B. The temperature rise
• C. Dew point is reached
• D. Evaporation takes place

Explanation: As moist air cools to its dew point, it becomes saturated and water vapour condenses on tiny particles to form cloud droplets or ice crystals. Rain is a later possible result, not the condition that starts cloud formation.

295. When a warm air is lifted off the surface in temperature depression it is called ________?

• A. An occlusion
• B. A cold front
• C. An anticyclone
• D. A warm front

Explanation: In an occlusion, a faster-moving cold front catches a warm front and lifts the warm air completely off the ground. A warm front lifts warm air gradually, but does not necessarily remove it from the surface.

296. Afternoon rains in the equatorial region are the result of influences _______?

• A. Land Breeze
• B. Monsoon
• C. Frontal
• D. Convectional

Explanation: Equatorial land heats strongly during the day, causing warm, moist air to rise and cool into clouds and rain. This vertical air movement produces convectional rainfall, not frontal or land-breeze rain.

297. The largest latitude circle on earth is ________?

• A. Arctic circle
• B. Tropic of cancer
• C. Tropic of Capricorn
• D. The Equator

Explanation: The Equator is at 0° latitude and forms the largest circle around Earth. Latitude circles become progressively smaller toward both poles, so the Arctic and tropics are smaller.

298. Rainfall related to mountains is:

• A. Orographic rainfall
• B. Normal rainfall
• C. Monsoon rains
• D. Cyclonic rainfall

Explanation: When moist air is forced to rise along a mountain slope, it cools and condenses, producing orographic rainfall. The opposite, drier side is called the rain-shadow region.

299. What kind of weathering takes place on the valley side above the surface of the glacier?

• A. Plucking
• B. Abrasion
• C. Chemical weathering
• D. Frost shattering

Explanation: Valley sides exposed above a glacier commonly undergo frost shattering, as water enters cracks, freezes, expands, and breaks the rock. Plucking and abrasion are mainly erosional actions performed by moving glacial ice.

300. During a total solar eclipse the rate of Photosynthesis___________?

• A. Increase
• B. Decrease
• C. Remain Constant
• D. None of them

Explanation: During a total solar eclipse, sunlight reaching plants falls sharply, reducing the light available for photosynthesis. The rate therefore decreases temporarily.