‘Population Doubling time’ means:

The correct answer is Option (1) → The time taken by any population to double itself at its current annual growth rate.

Option (1) The time taken by any population to double itself at its current annual growth rate. — Correct. This is the definition of population doubling time, word for word. The faster a population grows each year, the fewer years it needs to become twice as large.

Option (2) The time taken by population of a country to double itself in comparison to another country. — Incorrect. Doubling time comes from a population’s own annual growth rate; no second country enters it.

Option (3) The growth rate of the population is called ‘population doubling time’. — Incorrect. The growth rate is a percentage; doubling time is the number of years worked out from it.

Option (4) The natural growth of the population is called population doubling time. — Incorrect. Natural growth is the difference between births and deaths, a number of people, not a period of time.

NCERT: India - People and Economy — Chapter 1: Population: Distribution, Density, Growth and Composition, box ‘Population Doubling Time’ and the text beside it (2025-26)