NCERT Class 7 Geography — Chapter 1: Water

The correct option is

A-1, B-3, C-4, D-2

Explanation

Tides are the periodic rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon and the Sun, and the rotation of the Earth. The relative positions of these three bodies determine the magnitude (height) of the tides.

Statement-wise Analysis

• A. Sun, Moon, Earth in same line (Syzygy) → 1. Spring Tide
  When the Sun, Moon, and Earth are aligned in a straight line (either New Moon or Full Moon), their gravitational forces act in unison. This combined pull creates the maximum tidal range, known as Spring Tides.
• B. Moon in first/last quarter (Quadrature) → 3. Neap Tide
  When the Moon is at a right angle to the Sun relative to Earth (First and Third Quarter phases), the gravitational forces of the Sun and Moon counteract each other. The Sun's pull partially cancels the Moon's pull, resulting in tides of lower amplitude, known as Neap Tides.
• C. Highest tides → 4. Spring Tide
  Spring Tides represent the "highest high tides" and "lowest low tides" due to the additive gravitational force. Therefore, the phenomenon of the highest tides corresponds to Spring Tides.
• D. Low tides → 2. Neap Tide
  In this context, "Low tides" refers to tides with a small tidal range (lower high tides). Neap Tides occur when the difference between high and low water is minimized. Thus, they are associated with the lowest amplitude or "low" high tides.

List II contains duplicate entries for Spring and Neap tides. The matching logic assigns the specific instances (1, 2, 3, 4) to the corresponding descriptions (A, B, C, D) based on the correct conceptual pairing (A & C = Spring, B & D = Neap).

Key Takeaway

Spring Tides occur during the Full Moon and New Moon (straight-line alignment) and result in the highest tidal range. Neap Tides occur during the Moon's quarters (right-angle alignment) and result in the lowest tidal range.