Which of the following types of imaginary lines on a map join places that receive the same amount of rainfall?

Introduction / Context:
Meteorology and cartography use several types of imaginary lines to represent equal values of different variables on maps. Knowing the terminology for these lines helps in interpreting weather charts and thematic maps. This question specifically asks which type of line joins places that receive the same rainfall, so you must distinguish between terms used for equal elevation, equal pressure, equal depth and equal rainfall.

Given Data / Assumptions:
- The options list contour lines, isobaths lines, isohyets lines and isobar lines. - We must identify the term used for lines joining places with equal rainfall. - We assume standard geographical and meteorological terminology.

Concept / Approach:
Each prefix and suffix in these terms has a specific meaning. "Iso" means equal. "Hyet" comes from a Greek root relating to rain, so "isohyets" are lines joining points of equal rainfall. "Bar" refers to pressure, making isobars lines of equal atmospheric pressure. "Bath" relates to depth, so isobaths connect points of equal depth in oceans or lakes. Contour lines, commonly used on topographic maps, join points of equal elevation. Since the question focuses on equal rainfall, the correct term is isohyets.

Step-by-Step Solution:
Step 1: Recall that "iso" means equal in all these compound terms. Step 2: Recognise that "hyet" is associated with rain and rainfall, pointing to the term isohyets. Step 3: Recall that isohyets are specifically defined as lines on a map joining areas that receive the same amount of precipitation during a given period. Step 4: Identify that contour lines are unrelated to rainfall because they represent equal height or elevation. Step 5: Note that isobaths represent equal depth in water bodies, and isobars represent equal atmospheric pressure, neither of which concern rainfall. Step 6: Therefore, the correct answer is isohyets lines.

Verification / Alternative check:
If you have ever seen a rainfall distribution map, you may remember curved lines labelled with rainfall amounts, such as 500 mm or 1000 mm, connecting different regions. These are isohyets. Weather maps, on the other hand, often show isobars representing equal pressure, and topographic maps show contours for elevation. Distinguishing these typical usage patterns further confirms that isohyets correspond to equal rainfall.

Why Other Options Are Wrong:
Contour lines are wrong because they are used to show equal elevation above sea level, not rainfall.

Isobaths lines are wrong because they join points of equal depth in oceans, seas or lakes, not equal precipitation.

Isobar lines are wrong because they depict equal atmospheric pressure, commonly used in surface weather charts, rather than rainfall amounts.

Common Pitfalls:
Students sometimes confuse isohyets with isobars because both appear on meteorological maps. Others may not pay attention to the suffix and pick the term that sounds most familiar. To avoid these errors, break down each composite word into "iso" (equal) and the specific physical quantity: "bar" for pressure, "hyet" for rainfall, "bath" for depth and so on. This simple word analysis is often enough to arrive at the correct choice even if you have forgotten the exact definition.

Final Answer:
Imaginary lines that join places with the same amount of rainfall are called Isohyets lines.