Question

Time interval between a high tide and a low tide is
(A) 3 hrs 6 min
(B) 6 hrs 12 min
(C) 9 hrs 18 min
(D) 12 hrs 24 min

Answer 1

Hint: High and low tides are sourced by the moon, because the gravitational pull of the moon generates a force called tidal force. This tidal force causes the earth and its water to rise on the sides which are closest and farthest from the moon. These rises of water are known as high tides. Coastal areas encounter two high tides and two low tides every 24 hours and 50 minutes.

Complete step by step answer:
The earth rotates two tidal (Solar-day & Lunar day) bulges every lunar day, coastal areas experience two high and two tides every 24 hours 50 minutes. High tides occur with 12 hours 24 minutes difference in time.The main cause of tides in an ocean is the gravitational pull of the moon on the earth. Exact time interval between two high tides is 12 hours 24 minutes; however, the time interval between a huge tide and a low tide will be half of the time interval between two high tides.Therefore, the time interval between a high tide and a low tide is half of 12 hours 24 minutes, which is 6 hours 12 minutes.
The correct option is B, 6 hours 12 minutes.

Note:Another approach: Difference in time between two low tides will also be 12 hours 24 minutes. Every Solar day comprises 24 hours whereas every lunar day comprises 24 hours 50 minutes. This occurs because the moon revolution around the earth has the same direction as the earth’s rotation. Therefore, it takes extra 50 minutes for the earth to catch up with the moon. So, there will be two tidal bulges and we experience two high and two low tides every 24 hours 50 minutes.Therefore the difference in time between a high tide and a low tide is 6 hours 12 minutes.