Tides occur in the oceans and seas due to which among the following
- Gravitational force of the Sun
- Gravitational force of the Moon
- Centrifugal force of the Earth
Select the correct answer using the codes given below.
[UPSC Civil Services Exam – 2015 Prelims]
(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Answer: (d)
Explanation:
- Tides refer to the regular rising and falling of sea levels.
- They are mainly caused by the gravitational pull of the Moon, although the Sun’s gravitational pull and centrifugal force also have an effect.
- Water movements caused by wind and atmospheric pressure changes are referred to as surges.
- The force that generates tides is the difference between the gravitational pull of the Moon and the centrifugal force.
- Tides can vary in frequency, direction, and movement depending on location and time.
- They are classified based on frequency as semi-diurnal, diurnal, or mixed tides.
- Spring tides occur when the Sun, Moon, and Earth are in a straight line, resulting in higher tidal heights.
- Neap tides occur twice a month when the Moon and Sun are at right angles to each other, resulting in opposing forces that counteract each other.
Therefore, option (d) is the correct answer.
