NCERT Class 11 Geography — Chapter 2: Movements of Ocean Water

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The variation in the height of high tides is primarily determined by:

Official previous-year question

Verified 1 Aug 2026.

Options

AThe salinity of the water.
BThe temperature of the ocean water.
CThe position of sun and moon with respect to the earth.
DThe speed of the ocean currents.

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Solution

The correct option is The position of sun and moon with respect to the earth..

Explanation

Tides refer to the periodic rise and fall of sea levels caused principally by the combined effects of the gravitational forces exerted by the Moon, the Sun, and the rotation of the Earth. While the Moon's gravitational pull is the major cause, the Sun's gravitational pull and the centrifugal force due to Earth's rotation also play critical roles.

Analysis of Determinants

Position of Sun and Moon (Correct): The variation in the height of tides is primarily determined by the relative positions of the Sun, Moon, and Earth.
- Spring Tides: When the Sun, Moon, and Earth are aligned in a straight line (Syzygy), the gravitational forces of the Sun and Moon work together, resulting in the highest high tides. This occurs during the Full Moon and New Moon.
- Neap Tides: When the Sun and Moon are at right angles to each other relative to the Earth (Quadrature), their gravitational forces partially cancel each other out, resulting in lower high tides. This occurs during the first and third quarters of the moon.
Temperature, Currents, and Salinity (Incorrect): While factors like the shape of bays, estuaries, and local bathymetry can influence local tidal magnitude, the temperature of the water, the speed of ocean currents, and salinity are not the primary astronomical drivers determining the variation in tidal heights globally.

Key Takeaway: The primary factor governing the variation in the height of high tides (Spring vs. Neap tides) is the changing alignment of the Sun and Moon with respect to the Earth.

Your note

More from Chapter 2: Movements of Ocean Water

Consider the following factors: 1. The shape of bays and estuaries has no influence on the magnitude of tides. 2. Presence of wide continental shelves. 3. Presence of mid-oceanic islands. Which of the above factors can influence the height or magnitude of tidal bulges?

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Which of the following best describes the general movement of warm ocean currents?

easy

With reference to the movements of ocean water, consider the following statements: 1. Ocean currents represent the horizontal motion of water while tides represent the vertical motion. 2. In waves, the water moves ahead from one place to another along with the wave train. 3. The upwelling of cold water from the subsurface is a form of horizontal motion. Which of the statements given above is/are correct?

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Consider the following statements regarding the characteristics of ocean waves: 1. The largest waves are typically found in open oceans rather than enclosed seas. 2. Steep waves are generally old and originate from far away places. 3. Slow and steady waves usually originate from far away places. Which of the statements given above is/are correct?

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The maximum height of a wave is determined by which of the following factors? 1. The strength of the wind has no role in determining wave height. 2. The duration for which the wind blows. 3. The area over which the wind blows in a single direction. Select the correct answer using the code given below:

easy

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The correct option is The position of sun and moon with respect to the earth..

Explanation

Analysis of Determinants

Position of Sun and Moon (Correct): The variation in the height of tides is primarily determined by the relative positions of the Sun, Moon, and Earth.
- Spring Tides: When the Sun, Moon, and Earth are aligned in a straight line (Syzygy), the gravitational forces of the Sun and Moon work together, resulting in the highest high tides. This occurs during the Full Moon and New Moon.
- Neap Tides: When the Sun and Moon are at right angles to each other relative to the Earth (Quadrature), their gravitational forces partially cancel each other out, resulting in lower high tides. This occurs during the first and third quarters of the moon.
Temperature, Currents, and Salinity (Incorrect): While factors like the shape of bays, estuaries, and local bathymetry can influence local tidal magnitude, the temperature of the water, the speed of ocean currents, and salinity are not the primary astronomical drivers determining the variation in tidal heights globally.

Key Takeaway: The primary factor governing the variation in the height of high tides (Spring vs. Neap tides) is the changing alignment of the Sun and Moon with respect to the Earth.