Correct Answer - Option 4 : 24 hours 50 minutes
Tide: Tides are the rise and fall of the Sea levels caused by the combined effects of the gravitational forces exerted by the Moon and the Sun, and the rotation of the Earth.
Direct tides: At any given time, there are two high tides on the earth, the direct tide on the side facing the moon and the indirect tide on the opposite side. As the earth rotates on its axis, the location of the two diametrically opposed tidal bulges varies on the earth's surface.
- The solar day is of 24 hours and for Moon, it takes 24 hours and 50 minutes (a lunar day) for the same location on Earth to re-align with the moon.
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This is because the moon orbits the Earth in the same direction that the Earth rotates on its axis. This extra 50 minute means that the same location will experience high tides every 12 hours 25 minutes.
- Since the earth rotates through two tidal bulges, every Lunar day we experience two high tides and two low tides every 24 hours and 50 minutes. Here, we see the relationship between the Tidal cycle and the Lunar day.
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High tides occur 12 hours and 25 minutes apart, taking 6 hours and 12.5 minutes for the water at the shore to go from high to low, and then from low to high.
Hence, the correct answer is 24 hours and 50 minutes.
Tide changes proceed through the following stages:
- Sea level rises over several hours, covering the intertidal zone; flood tide.
- The water rises to its highest level, reaching high tide.
- Sea level falls over several hours, revealing the intertidal zone; ebb tide.
- The water stops falling, reaching low tide.
