Geographical Techniques Questions and Answers

Answer: A

The local time is 6:00 p.m.

The Earth turns 360° in 24 hours, so each degree of longitude makes a difference of 4 minutes. Thimphu is 90° east of Greenwich:

\[ 90 \times 4 = 360\ \text{minutes} = 6\ \text{hours} \]

Places east of Greenwich are ahead in time, so when it is 12 noon at Greenwich it is 6:00 p.m. at 90° E. 6:00 a.m. is what a place 90° west would have.

Answer: C

The answer is 179.

Latitudes are drawn from the equator (0°) to the poles (90° N and 90° S). At 1° intervals there are 89 parallels in each hemisphere, from 1° to 89°, plus the equator:

\[ 89 + 89 + 1 = 179 \]

The poles are points, not circles, so they are not counted as parallels. This is the count given in NCERT's geography textbook. 180 and 178 come from miscounting the equator or the poles.

Answer: B

The time at 45° E is 3 p.m.

The Earth turns 360° in 24 hours, so local time changes by 4 minutes for each degree of longitude, and places east of Greenwich are ahead of it.

\[ \begin{aligned} 45 \times 4 &= 180 \text{ minutes} = 3 \text{ hours} \\ 12 \text{ noon} + 3 \text{ h} &= 3 \text{ p.m.} \end{aligned} \]

9 a.m. is the result of subtracting the 3 hours, which would be right for 45° W. 10 a.m. and 2 p.m. are 2 hours either way, which comes from using the wrong rate of change.

Answer: B

The correct statement is Tropic of Capricorn passes through southern hemisphere.

The Tropic of Capricorn is the parallel at 23½° south of the equator, so it lies in the southern hemisphere.

The other statements are wrong. The Arctic Circle is at 66½° north and the Antarctic Circle at 66½° south; 23½° is the latitude of the tropics. The Tropic of Cancer is at 23½° north, so it passes through the northern hemisphere, not the southern.

Answer: A

The line is the Equator.

The Equator is the imaginary circle drawn midway between the North Pole and the South Pole. It is the 0° latitude and the longest parallel, and it divides the globe into two equal halves, the northern and the southern hemispheres.

The Tropic of Cancer (23½° N), the Tropic of Capricorn (23½° S) and the Arctic Circle (66½° N) are all smaller circles away from the middle, so none of them divides the globe into equal parts.

Answer: D

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

A globe has the network of latitudes and longitudes drawn on it (A). It is fixed on a needle that is tilted, like the Earth's axis, so it tilts on its axis (B). And because it is a miniature sphere, it is described in textbooks as a true model of the Earth, unlike a map, which distorts shapes and sizes (C).

Statement D is false: a globe is spherical, not oval. Every option that includes D is therefore wrong.

Answer: B

When it is 10 a.m. in India, it is around noon in Singapore.

Indian Standard Time is 5 hours 30 minutes ahead of UTC, and Singapore time is 8 hours ahead, so Singapore is 2 hours 30 minutes ahead of India:

\[ 10{:}00 + 2{:}30 = 12{:}30 \]

which is around noon.

Japan is 3 hours 30 minutes ahead of India, so it would be 1:30 p.m. London is behind India (by 5 hours 30 minutes in December), so it would be early morning there. Karachi, on Pakistan time, is 30 minutes behind India, so it would be 9:30 a.m.

Answer: C

The correct method is dividing the total length of the Equator by 360.

There are 360 degrees of longitude around the earth, 180 east and 180 west of the Prime Meridian, and the meridians are drawn at one-degree intervals. At the Equator they are therefore spaced equally around a full circle, so the distance between two neighbouring meridians is the Equator's length divided by 360.

\[ \begin{aligned} d &= \frac{40{,}075\ \text{km}}{360} \\ &\approx 111\ \text{km} \end{aligned} \]

Dividing by 180 counts only one hemisphere's meridians and doubles the answer to about 222 km. Dividing double the length by 90 gives eight times the true figure, and dividing half the length by 360 gives half of it.

Answer: A

Maps are best used for marking places where people have lived at different points in history.

A historical map shows space: where settlements, kingdoms, river valleys and trade routes were. By marking the sites where people lived at different times, it helps learners see why they chose those places, such as near rivers or fertile land.

The other uses are not what maps do best. Arranging events in sequence is the job of a timeline. Elaborating on important events needs written or oral accounts. Studying people's lives in a logical time sequence again calls for chronology and sources, not a map.

Answer: C

It will be 9:00 a.m. and 5:00 p.m. respectively.

The earth turns 360° in 24 hours, so local time changes by 4 minutes for each degree of longitude: later towards the east and earlier towards the west.

\[ \begin{aligned} 60 \times 4\ \text{min} &= 240\ \text{min} \\ &= 4\ \text{hours} \end{aligned} \]

At 60° West the time is 4 hours behind Greenwich: 1:00 p.m. minus 4 hours is 9:00 a.m. At 60° East it is 4 hours ahead: 1:00 p.m. plus 4 hours is 5:00 p.m.

'5:00 p.m. and 9:00 a.m.' puts the west ahead of Greenwich and the east behind it, the wrong way round. '5:00 a.m. and 9:00 p.m.' uses 8 minutes a degree, doubling the difference, and '9:00 p.m. and 5:00 a.m.' makes both mistakes at once.