Question map
Statement I : Tides are the 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. Statement I : The Earth rotates from west to east.
Explanation
Statement I is true as tides are the periodic rise and fall of sea levels primarily caused by the gravitational attraction of the Moon and Sun, combined with the centrifugal force arising from the Earth's rotation [3]. These forces create two tidal bulges: one on the side facing the Moon due to gravity and another on the opposite side due to centrifugal force [2]. Statement II is also true; the Earth rotates on its axis from west to east. However, Statement II is not the correct explanation for Statement I. While the Earth's rotation creates the centrifugal force necessary for the second bulge and determines the frequency of tides as landmasses pass through these bulges, the direction of rotation (west to east) is not the fundamental reason why tides occur or how the gravitational-centrifugal balance functions [3].
Sources
- [1] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 13: Movements of Ocean Water > TIDES > p. 109
- [3] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 32: Ocean Movements Ocean Currents And Tides > 32.2. Tides > p. 500
- [2] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 32: Ocean Movements Ocean Currents And Tides > Tidal Bulge: Why There Are Two Tidal Bulges? > p. 501