Geographical Techniques Questions and Answers

Answer: B

The correct matching is (a) i, (b) iv, (c) ii, (d) iii, option B. A planimeter measures the area on a map, a clinometer (printed Elinometer) measures the elevation or the angle of a land surface, a pantograph is used for the reduction and enlargement of maps, and a barometer measures the air pressure of a place. Options A, C and D swap the pantograph, the clinometer or the planimeter. Each row is checked against the four codes in turn, since a single wrongly paired item rules a code out and only one code is right for all four rows.

Answer: C

Both statements are true, option C. The scale of an air photograph over flat terrain is given by the focal length of the camera divided by the height of the aircraft above the ground, so it depends upon both the height of the aircraft, which lowers the scale as it rises, and the focal length of the camera, which raises it as it gets longer. Options A, B and D take one or both factors as false. The other options name places, people or terms that the subject does not connect with this question, so only the keyed option stands.

Answer: C

Both statements are correct, option C. On a convex slope, which is gentle at the top and steep at the foot, the contours are close together at the foot and farther apart at the top. In general, the closeness of the contours indicates the steepness of the slope. Options A, B and D deny one or both statements. The other options name places, people or terms that the subject does not connect with this question, so only the keyed option stands.

Answer: A

The maps in decreasing order of scale are the cadastral map, the topographical map, the wall map and the atlas map, (ii), (iii), (iv), (i), option A. A cadastral map shows plots of land on a very large scale, a topographical map is on a medium scale, a wall map is on a smaller scale, and an atlas map is on the smallest scale of the four. The other options place the atlas or the wall map at the large end. The other options name places, people or terms that the subject does not connect with this question, so only the keyed option stands.

Answer: D

Neither statement is correct, option D. In a dot map the value of each dot is kept constant, so that the density of the dots shows the density of the thing mapped, and statement (a), which says that the value varies, is wrong. Statement (b) is also wrong: a dot map shows the distribution of countable things, such as the population or the agricultural production, but rainfall is a continuous quantity that is shown by isohyets, and not by dots. So options A, B and C are wrong.

Answer: C

The correct match is visible region with 0.4 to 0.7 micrometre, near infrared with 0.7 to 3.0 micrometre, microwave with 1 mm to 1 metre and thermal infrared with 8 to 12 micrometre, so iv iii ii i.

The wavelengths increase in the order visible, near infrared, thermal infrared and microwave, and these ranges are the standard ones used in remote sensing.

The other codes give the visible region the near infrared range or the thermal infrared the microwave range, which is wrong.

Answer: A

Flow maps are used to show line data.

A flow map represents movements, such as traffic, trade or migration, by lines whose width is drawn in proportion to the volume carried.

Area data (option B) are shown on choropleth maps, point data (option C) by dots and symbols, and volume (option D) by methods such as block diagrams.

A flow line map is therefore a way of showing movement along a route, so the quantity shown is carried by the width of the line, such as the thick band for a busy railway line between two cities and the thin one for a minor route.

Answer: C

A cumulative frequency distribution is shown by an ogive.

An ogive is drawn by plotting the running total of frequencies against the class limits and joining the points with a smooth curve.

A histogram (option A) and a frequency curve (option B) show the frequencies in each class, not the running total, and a pie diagram (option D) shows the shares of a whole.

To draw an ogive one adds the frequencies class by class, plots each total at the upper class limit, and joins the points, and the curve always rises from left to right since the totals never decrease.

Answer: B

The correct matching is standard distance with the centrographic measure, nearest neighbour with settlement pattern, correlation with the scatter diagram and eigen value with principal component, that is iv, iii, ii, i.

The other combinations give a statistic the wrong analysis, such as eigen value with scatter diagram, so the second option is the only one that is right.

Answer: C

Map overlaying is a GIS operation. Overlay combines two or more layers of spatial data to find places where conditions coincide, and it is one of the core functions of a GIS.

Image displaying and contrast stretching belong to image processing in remote sensing, and map designing is cartography, so they are not the GIS operation asked for.