For what the process of 'Time Lapse Analysis' is used in the time measurement process ?
(a) Leap Year
(b) Adhik Mass
(c) Kshay Mass
(d) Tithi Vridhhi - lope
Choose correct answer.

Question

UnlockIAS · Accepted Answer

Correct — option (4), '(a), (b), (c), (d)'. Every one of the four named items exists for the same reason, so all four belong to the same family of corrections. The reason is that the three natural clocks humans reckon time by are not whole multiples of one another: the civil day is 24 hours, the synodic month (new moon to new moon) is about 29.53 days, and the tropical year is about 365.2422 days. No calendar can hold all three in step on its own, so every calendar carries a correction that periodically adds or drops a unit. Statement (a), the leap year, is the day-level correction: because the tropical year runs about a quarter of a day past 365, a day is added every fourth year, and because that over-corrects slightly, century years are not leap years unless divisible by 400. Statement (b), Adhik Mass, is the month-level correction in the Indian luni-solar calendar: twelve lunar months make about 354 days, roughly 11 days short of the solar year, so an extra thirteenth month is intercalated about every 32 to 33 months — the working rule being that a lunar month in which no sankranti (the Sun's entry into a new rashi) falls is declared adhika. Statement (c), Kshay Mass, is the same correction running the other way: a lunar month that contains two sankrantis is dropped altogether. Statement (d), Tithi Vridhhi-lope, is the day-level correction inside the lunar reckoning: a tithi is one-thirtieth of a lunation, defined as each 12 degrees by which the Moon pulls ahead of the Sun, and because both bodies move at varying apparent speeds a tithi runs anywhere from roughly 19 to about 26 hours. A tithi that begins and ends between two sunrises touches no sunrise and is omitted (lopa or kshaya); one that spans two sunrises is repeated (vriddhi). Insertion, deletion, repetition, omission — four devices, one purpose. Option (4) is the only choice that contains all four, and it is right here not because it is the longest option but because each named item can be shown, independently, to belong.

Why the other options are wrong — (a) Keeps only the two month-level devices, Adhik Mass and Kshay Mass, and throws out both day-level ones. That is an arbitrary cut: the leap day and the tithi vriddhi-lopa rule do exactly the same job at a finer grain — they absorb the fractional remainder that the larger unit cannot hold. A candidate lands here by reading the question as being about the Hindu lunar month specifically, when the stem asks about the process of time measurement in general and lists a Gregorian device, (a), in the same breath as three panchang devices.  (b) Keeps Kshay Mass and Tithi Vridhhi-lope but drops Adhik Mass, which is the single most familiar and most frequently applied of the four — it recurs about every third year, whereas a kshaya masa is rare. Any pairing that admits the deletion of a month while excluding the insertion of one is internally inconsistent, because both follow from the same sankranti test applied to a lunar month: no sankranti means adhika, two sankrantis mean kshaya.  (c) The narrowest reading — that only the Gregorian leap year counts as a time-drift correction. It fails on the plain content of the other three: adhika masa, kshaya masa and tithi vriddhi-lopa are all documented adjustments in Indian calendrical practice, printed every year in every panchang, and each one exists precisely to reconcile a reckoning unit with the astronomical period it is meant to track. Choosing (3) requires treating 'time measurement' as a purely Western calendrical exercise, which the stem's own list contradicts.

Concept: A calendar is an attempt to build whole numbers out of periods that are not whole. The day is set by the Earth's rotation, the month by the Moon's revolution around the Earth, and the year by the Earth's revolution around the Sun; none divides evenly into another. Three answers exist. A purely solar calendar (Gregorian) tracks the year and lets the month drift free of the Moon, paying for the year's fractional quarter-day with a leap day. A purely lunar calendar (Hijri) tracks the Moon and lets its year of about 354 days slide backwards through the seasons. A luni-solar calendar — which is what the Indian panchang is — refuses to give up either, and therefore needs the heaviest machinery: an intercalary month (adhika masa) to make up the roughly eleven-day annual shortfall, a suppressed month (kshaya masa) when the correction overshoots, and a rule for tithis that do not line up with sunrise, giving repeated tithis (vriddhi) and omitted ones (lopa or kshaya). The four items in this question are simply the four rungs of that one ladder.

State PCS 2026 Q21 — Geography PYQ with Answer

State PCS 2026 Q21 — Geography PYQ with Answer