Which of the following statements regarding neap tides is/are correct? 1. It occurs every 14 – 15 days, which coincides with the first and third quarter of the Moon. 2. This tide has a small tidal range because the gravitational forces of the Moon and the Sun are in quadrature. Select the answer using the code given below:
- (a)1 only
- (b)2 only
- (c)Both 1 and 2
- (d)Neither 1 nor 2
Correct — C, both statements 1 and 2. A neap tide occurs when the Moon is at its first quarter and again at its third quarter — the two occasions roughly 14-15 days apart in the lunar month — so statement 1 is true. At those quarter phases the Sun and the Moon lie at right angles to each other as seen from the Earth (a position called quadrature). Their tide-raising gravitational pulls act at 90 degrees and therefore partly oppose one another, so the difference between high water and low water shrinks to its smallest — a low tidal range. That is exactly what statement 2 says, so it is true as well. With both statements correct, the answer is (c).
- (a)1 only — Accepts the timing but rejects the cause. Statement 2 is also correct — the small range of a neap tide is precisely because the Sun and Moon pull in quadrature, so this option wrongly drops a true statement.
- (b)2 only — Accepts the cause but rejects the timing. Statement 1 is correct — neap tides do coincide with the first and third quarters of the Moon, about a fortnight apart — so this option is incomplete.
- (d)Neither 1 nor 2 — Both statements are actually correct, so denying both is wrong. Quarter-phase timing and quadrature-driven small range are the defining features of a neap tide.
Tides are the periodic rise and fall of sea level caused by the gravitational pull of the Moon and, to a lesser extent, the Sun, together with the centrifugal effect of the Earth-Moon system. When the Sun and Moon line up (new and full Moon) their pulls add to give the large-range spring tide; when they lie at right angles (first and third quarter) their pulls partly cancel to give the small-range neap tide.
The trap is to confuse neap with spring tides or to think a neap tide is simply a weak version at the same phase. The key is the geometry — quadrature means a 90-degree Sun-Earth-Moon angle, which is what makes the range small. Spring and neap tides alternate about every week, so consecutive neaps are roughly 14-15 days apart.
- Neap tides happen at the first quarter and third quarter of the Moon, about 14-15 days apart within the lunar cycle.
- At those phases the Sun and Moon are in quadrature (at right angles to the Earth), so their tide-generating forces partly cancel and the tidal range is at its smallest.
- Spring tides, by contrast, occur at new Moon and full Moon when the Sun and Moon are in line (syzygy) and their pulls reinforce, giving the largest range.
- The Moon is the dominant tide-raiser because, although far less massive than the Sun, it is much closer, and tidal force falls off with the cube of distance.
A neap tide is defined by quarter-Moon timing and a right-angle (quadrature) Sun-Moon geometry — both statements in the question describe it, so the answer is (c).
- Swapping neap and spring tides — remember quarter Moon and quadrature go with the small-range neap tide.
- Thinking the Sun has no role — it does, but because it is far away its tidal effect is only about half the Moon's, so it modulates rather than dominates.
Asked as a statement-code question that pairs the timing (quarter Moon, 14-15 days) with the cause (quadrature) — verify both to reach (c).
Assertion (A): During the Neap Tides, the high tide is lower and the low tide is higher than usual. Reason (R): The Neap Tide, unlike the Spring Tide, occurs on the New Moon instead of on the Full Moon.
- (a) Both A and R are individually true, and R is the correct explanation of A
- (b) Both A and R are individually true, but R is NOT a correct explanation of A
- (c) A is true, but R is false
- (d) A is false, but R is true
Answer(c) A is true, but R is false — a neap tide does give a lower high and higher low (small range), but it occurs at the quarter Moon, not on the new Moon.
Tests the very same neap-tide concept — its small range and its correct timing at the quarter phases, not the new Moon — mirroring both statements in this NDA question.
Tides occur in the oceans and seas due to which among the following? 1. Gravitational force of the Sun 2. Gravitational force of the Moon 3. Centrifugal force of the Earth
- (a) 1 only
- (b) 2 and 3 only
- (c) 1 and 3 only
- (d) 1, 2 and 3
Answer(d) 1, 2 and 3 — tides arise from the combined gravitational pull of the Sun and Moon plus the centrifugal effect of the Earth-Moon system.
Covers the tide-generating forces that lie behind spring and neap tides — the same Sun-plus-Moon mechanism whose alignment (quadrature) makes a tide 'neap'.
- practice — not a real PYQ
Spring tides of the largest range occur when the Sun, Earth and Moon are:
- (a)at right angles (quadrature)
- (b)in a straight line (syzygy)
- (c)at the Moon's apogee only
- (d)at the first quarter only
Answer(b) in a straight line (syzygy) — at new and full Moon the Sun's and Moon's pulls reinforce, giving the largest tidal range.
- practice — not a real PYQ
The chief reason the Moon raises higher tides than the Sun is that the Moon is:
- (a)more massive than the Sun
- (b)much closer to the Earth
- (c)hotter than the Sun
- (d)always at quadrature
Answer(b) much closer to the Earth — tidal force falls off with the cube of distance, so nearness outweighs the Sun's far greater mass.