Climatology in Geography Questions and Answers

Answer: C

A wind vane is used for measuring wind direction.

A wind vane (weather vane) is a pointer mounted on a vertical axis. Its broad tail catches the wind, so the arrow swings round to point into the wind, showing the direction from which it blows. It is often fitted with letters for the cardinal directions.

Wind velocity is measured with an anemometer, air pressure with a barometer and air temperature with a thermometer. These are the instruments of a weather station, and the question tests which one goes with the vane.

Answer: C

The layer that helps radio transmission is the thermosphere.

In the thermosphere, which lies above the mesosphere at roughly 80 to 400 km, the gases are ionised by solar radiation. This ionised region, the ionosphere, reflects radio waves back to the earth, which is what makes long-distance radio transmission possible. NCERT's Class VII geography book states this directly.

The stratosphere holds the ozone layer and suits jet aircraft; the mesosphere is where meteors burn up; the exosphere is the thin outermost layer that merges into space.

Answer: B

Seasons change because the earth's axis of rotation is tilted with respect to the plane of its orbit.

The axis is tilted at about 23.5° and keeps pointing in the same direction as the earth goes round the sun. So for part of the year the northern hemisphere leans towards the sun, getting more direct rays and longer days (summer), and six months later it leans away (winter).

A perpendicular axis would give equal days and nights and no seasons all year. The earth-sun distance changes only slightly, and the earth is actually nearest the sun in January, during the northern winter.

Answer: A

Meteorites burn up in the Mesosphere.

The mesosphere, the third layer of the atmosphere, lies above the stratosphere and extends up to about 80 km. NCERT notes that meteorites burn up in this layer on entering from space, as friction with the air heats them.

The stratosphere below it contains the ozone layer and is suited to aircraft. The thermosphere above it, where temperatures rise rapidly, contains the ionosphere used for radio transmission. The exosphere is the outermost layer, with very thin air. None of these is the layer named for burning up meteors.

Answer: C

The answer is both A and B are true.

Permanent winds, also called planetary winds, blow constantly throughout the year in a particular direction (A). NCERT names the trade winds, the westerlies and the easterlies as permanent winds (B).

They are distinguished from seasonal winds, such as the monsoons, which change direction with the seasons, and from local winds such as the loo, which blow only over a small area and for a short period. Since both statements are true, the options marking either of them false are wrong.

Answer: D

The answer is both A and B are false.

Statement A describes weather, not climate. Weather is the day to day condition of the atmosphere; climate is the average weather of a place over a long period, usually about 30 years or more.

Statement B is false because of the word 'only'. The climate of a place depends on several factors: its latitude, altitude and relief, its distance from the sea, ocean currents and the prevailing winds. Since both statements are wrong, the options marking either of them true are wrong.

Answer: B

The true statement is The mid-day Sun never shines overhead on any latitude beyond the Tropic of Cancer and the Tropic of Capricorn.

Because the Earth's axis is tilted at about 23½°, the overhead Sun moves only between the Tropic of Cancer and the Tropic of Capricorn. Every latitude between them gets the Sun directly overhead at least once a year; no latitude beyond them ever does.

The other statements are false. The temperate zone in the northern hemisphere lies between the Tropic of Cancer and the Arctic Circle, not from the Equator. The low, slanting Sun is a feature of the frigid zones near the poles, not of the whole southern hemisphere. And the latitudes between the Tropic of Cancer and the Arctic Circle never have the Sun overhead.

Answer: A

Statements A and B are correct, so the answer is Only A and B.

The temperate zones have moderate temperatures, neither very hot nor very cold (A). They lie beyond the tropics, so the mid-day Sun never shines overhead on any latitude in them (B).

Statement C is wrong on two counts. A temperate zone does not reach the Equator: in the north it lies between the Tropic of Cancer and the Arctic Circle. And it is not confined to the northern hemisphere, since there is a matching South Temperate Zone between the Tropic of Capricorn and the Antarctic Circle. So the options containing C are wrong.

Answer: B

The second most plentiful gas in the air is oxygen.

Dry air is about 78 per cent nitrogen and about 21 per cent oxygen. Argon makes up most of the remaining 1 per cent, and carbon dioxide only about 0.04 per cent.

Nitrogen is the most plentiful gas, not the second. Carbon dioxide, though important for plants and for the greenhouse effect, is present only in a tiny fraction, and hydrogen occurs only in traces, so neither comes close to second place.

Answer: C

The true statements are A, C and D, so the answer is A, C and D.

High pressure is associated with clear, sunny skies (A), and low pressure with cloudy skies and wet weather (C). Air always moves from areas of high pressure to areas of low pressure, which is what creates wind (D).

Statement B is false. Air pressure is strongly influenced by temperature: when air is heated it expands, becomes lighter and rises, creating an area of low pressure, while cold air is dense and sinks, creating high pressure. So every option that includes B is wrong.