Previous Year Question

Tides primarily result from the combined effect of the unequal gravitational attraction exerted by the Sun and the Moon on different parts of the Earth and the centrifugal or inertial effect associated with the Earth-Moon system.

Gravitational force of the Sun: The Sun’s gravitational attraction exerts a tide-generating force on ocean water. The Sun is extremely massive, but because it is very far from the Earth, its tidal effect is approximately half that of the Moon.

Gravitational force of the Moon: The Moon is much closer to the Earth and is therefore the most influential celestial body in producing tides. Its stronger attraction on the side of the Earth facing the Moon creates one tidal bulge.

Centrifugal force: The Earth and the Moon revolve around their common centre of mass. The centrifugal or inertial effect associated with this system contributes to the formation of a second tidal bulge on the side of the Earth opposite the Moon.

When the Sun, Earth and Moon are aligned, their tidal effects combine to produce spring tides. When the Sun and Moon are at right angles relative to the Earth, their effects partially counteract each other and produce neap tides.