Question

A line on a map joining place of equal temperature is called an_______.
a.Isohyets
b.Isobars
c.Isotherms
d.Isohalines

Answer 1

Hint: Temperature is a physical quantity that conveys the hotness and coldness of a body. It is estimated with the help of a thermometer. The contour lines which indicate elevation on a map by adjoining points of equal elevation, for example are called Isolines. These imaginary lines provide a good visual presentation of the topography.

Complete Answer:
a) An isohyet is a line on a map which connects points that have the identical amounts of precipitation in a given interval. The technique used in estimating average rainfall across a specific region is known as an isohyetal method. This method is used while drawing lines of equal precipitation on a map. Thus, option 'a' is incorrect.

b) Isobars are lines on a weather map joining places of equal atmospheric pressure. It measures the atmospheric pressure in millibars and is drawn at a difference of two or four millibars. The closer the spacing of isobars , the windier it is.
If the lowest number is in the middle circle, this is a low pressure which is marked by wet and windy weather. If the highest number is in the middle circle, this is a high pressure which is marked by dry and sunny weather. Thus, option 'b' is incorrect.

c) Isotherms are lines drawn on a map joining points with the same temperature. They are generally used in meteorology to show the ratio of temperature at the Earth’s surface or on a chart demonstrating steady level or steady pressure. They are also used to indicate the time variation of temperature with height in the atmosphere or with depth in soil or water. Thus, this option is correct.

d) Isohalines are lines drawn on the surface of a map to demonstrate connecting points of equal salinity in the ocean.

The correct option is 'c'.

Note: Alexander von Humboldt is known as the father of isotherms. He was the first to comprehend that isothermal lines cut through latitudes at different angles, thus questioning the prevailing scientific belief that climate depended entirely on latitude. Apart from contours and isobars there are many more isolines used in geography, although quite a few of them are used only by professionals and they are barely ever heard of in school.