Geographical Techniques Questions and Answers

Answer: C

The coefficient of variation is a relative measure of dispersion: it is the standard deviation divided by the mean, expressed as a percentage. Because it has no units, it can be used to compare the spread of data sets with different units or different averages.

Standard deviation, quartile deviation and range are absolute measures of dispersion, expressed in the units of the data. The coefficients of quartile deviation and range are relative, but the option names the quartile deviation and the range themselves.

Answer: B

When a map drawn at RF 1/5,500 is reduced to half its size, every distance on it becomes half as long, so the denominator doubles to 11,000. The new representative fraction is 1/11,000.

1/2,750 would be an enlargement to twice the size, and 1/5,000 and 1/33,000 are not related by a factor of two to the original. A smaller map means a smaller fraction, so option B is correct.

Answer: D

Neither statement is correct. The national acquisition and distribution agency for satellite data in India is the National Remote Sensing Agency (NRSA, now the National Remote Sensing Centre) at Hyderabad, and not NASA, which is the American space agency.

In the second statement, the data are passed on to the NNRMS, the National Natural Resources Management System, but the sender is the NRSA, not NASA, so this is also wrong as worded. Options A, B and C each accept one or both statements.

Answer: D

Statements 1, 2 and 4 are correct, so the answer is D. In a representative fraction the numerator is one, the units of numerator and denominator are the same, and a statement scale such as 1 cm to 1 km is a suitable way to show scale.

Statement 3 is false, because the RF is a recognised technique for showing scale. Options A, B and C, which include statement 3, are therefore wrong.

Statement 4 is accepted because a statement of scale such as '1 cm to 1 km' is easy to read for a general user, although it becomes wrong when the map is enlarged or reduced. Statement 3 contradicts the standard use of the R.F., which has no unit and works in any system of measurement.

Answer: C

The RF of the reduced map is 1/15,000. Reducing the map to one third of its size makes the denominator three times larger, so 5,000 x 3 = 15,000.

1/2,500 and 1/1,000 would be enlargements, and 1/25,000 would be a reduction by five times, not three.

As a check, a map drawn at 1/15,000 shows a 1 cm length for 150 m on the ground, whereas the original 1/5,000 map showed 1 cm for 50 m, so each feature is drawn one third as long. A larger denominator always means a smaller scale and a more reduced map.

Answer: A

Only statement 1 is correct, so the answer is A. The Indian Remote Sensing (IRS) satellite programme is the mainstay of the National Natural Resources Management System (NNRMS), which uses its data for resource mapping and monitoring.

The official key does not accept statement 2 as correct, so options B and C, which accept it, are wrong, and option D, which rejects statement 1 as well, is wrong because statement 1 is true.

IRS satellites, launched by India since 1988, give data for agriculture, forests, water, geology and land use, and the NNRMS uses those data for planning at the national level, so it is right to call them the mainstay of the system.

Answer: C

The correct statement is that the scale of cube roots is used for showing the spheres. In Sten De Geer's method, population is shown by spheres drawn so that the volume of each sphere is proportional to the number of people, so the radius is found from the cube root of the value.

The method is used mainly for urban population and not rural, so A and B are wrong (dots are used in the dot method). Spheres occupy more space on the map in comparison with dots, but the key chooses the cube-root scale as the correct description, and D is not accepted.

Answer: C

The Gini index is used to measure inequality in the distribution of farmers' income according to the size of their landholdings. It compares the cumulative share of income with the cumulative share of people or holdings, and a value near 0 means equal distribution while a value near 1 means high inequality.

Standard deviation and coefficient of variation measure the spread or relative variation of values, and the correlation coefficient measures how two variables vary together. None of them is the standard measure of inequality of distribution.

Answer: A

Statements (a) and (b) are correct. Random sampling is called probability sampling, since each unit has a known chance of selection, and it is done with the help of a table of random numbers.

Statement (c) is not accepted, since landscape elements are not generally scattered at random and the key does not count it. Options B, C and D, which include (c), are therefore wrong.

Random sampling gives every member of the population an equal chance of being selected, and a table of random numbers is the usual device for choosing the sample points. Landscape elements are not usually scattered by chance, because they follow soil, relief and settlement, so statement (c) fails.

Answer: B

The correct matching is a-ii, b-iii, c-i, d-iv. The chorochromatic method uses colours for areas such as an administrative map, the choroschematic method uses letters or symbols such as R for rice and W for wheat, isopleth maps show contours and other lines of equal value, and the choropleth method shows density of population with shades of one colour.

The other codes pair chorochromatic and choroschematic the other way round or give isopleth the density map, so only B matches.