CDS Geography · Indian Geography — Economy, Resources and Transport
Population Size and Growth
Which States have the most people and the most crowding, how India's population growth passed through four phases, and what the Census means by literacy, infant mortality and a young population.
Why this matters
Eleven CDS questions from 2016 to 2026. Four ask you to rank States by population or density, which needs the 2011 Census figures in your head. The others test the phases of growth and the exact definitions the Census uses.
Concept 1 of 3: State populations and density
Population density is simply people per square kilometre. A big State can have many people and still be thinly spread; a small one can be crowded. CDS likes to set four States in a row and ask for the right order, so learn the few numbers below rather than guessing from the map.
Definition
All figures are from the 2011 Census, the latest complete count:
- India had about 121 crore people and a density of 382 persons per square kilometre.
- Uttar Pradesh is the most populous State (about 20 crore). Sikkim has the fewest people.
- Bihar is the most densely populated State (1,106 per sq km). Arunachal Pradesh is the least (17).
- In the north-east, Assam is by far the densest (398), against Meghalaya (132), Nagaland (119) and Arunachal (17).
| States compared | Census 2011 figures |
|---|---|
| Kerala, Jharkhand, Assam, Punjab (population) | 3.34 crore, 3.30 crore, 3.12 crore, 2.77 croreQ CDS 2016 (II): Kerala, Jharkhand, Assam, Punjab is the decreasing order. |
| Meghalaya, Goa, Mizoram, Sikkim (population) | 29.7 lakh, 14.6 lakh, 10.9 lakh, 6.1 lakhQ CDS 2019 (I): Meghalaya is the most populous of these four. |
| Arunachal, Mizoram, Sikkim, Himachal (density) | 17, 52, 86, 123 per sq kmQ CDS 2018 (II): this is the ascending order of density. |
| Assam, Meghalaya, Nagaland, Arunachal (density) | 398, 132, 119, 17 per sq km |
| Bihar and Arunachal Pradesh (density) | 1,106 (highest) and 17 (lowest) per sq km |
Practice this conceptself-check · 4 quick reps
The same idea in a real exam question:
CDS · 2021 · CDS (II) 2021 — General Knowledge · Q40Moderate
Example 1 · Indian Geography — Economy, Resources and Transport · Population Size and Growth
In a discussion, M from Arunachal Pradesh, J from Assam, N from Meghalaya and S from Nagaland are claiming that as per Census 2011, their State has the maximum density of population. Identify the person making the correct claim.
Kerala just beats Jharkhand
In 2011 Kerala (3.34 crore) had slightly more people than Jharkhand (3.30 crore). Options that put Jharkhand first are the trap; then come Assam, then Punjab.
Large is not dense
Arunachal Pradesh is the largest north-eastern State but the least dense in all India (17). Assam (398) is the densest in the north-east.
Concept 2 of 3: Phases of population growth
India's population did not grow at one steady speed. It stood almost still until 1921, then grew steadily as famines and epidemics were controlled, then shot up after 1951 as the death rate fell fast while families stayed large. Since 1981 the growth rate has been falling, though the numbers keep rising.
Definition
- The decadal growth rate is the change in population over ten years, as a percentage of the population at the start.
- A Census year names the decade that ends in it: '1971' means the decade 1961 to 1971.
- 1921 is the demographic divide: growth was stagnant before it and never fell back after it.
- Growth was highest in 1961 to 1971 (about 24.8 per cent), just above 1971 to 1981 (about 24.7). It fell to about 17.7 per cent in 2001 to 2011.
- In 2001 to 2011 growth slowed in almost every State. Tamil Nadu was an exception: its growth rose from about 11.7 to about 15.6 per cent.
| Period | Phase |
|---|---|
| 1901 to 1921 | Stagnant or stationary growth |
| 1921 to 1951 | Steady growth |
| 1951 to 1981 | Population explosion; peak growth of about 24.8 per cent in 1961 to 1971Q CDS 2020 (II): decadal growth was highest in the Census year 1971. |
| 1981 onwards | Growth still high but steadily slowing |
Practice this conceptself-check · 4 quick reps
The same idea in a real exam question:
CDS · 2022 · CDS (I) 2022 — General Knowledge · Q35Moderate
Example 2 · Indian Geography — Economy, Resources and Transport · Population Size and Growth
In India, the period of steady population growth refers to the decade(s) of :
A Census year names the decade that ends
The highest decadal growth was in 1961 to 1971, recorded at the 1971 Census. An option '1961' points to the decade 1951 to 1961, which grew more slowly.
Steady is not explosive
1921 to 1951 is steady growth. 1951 to 1981 is the population explosion. Swapping the two is the usual trap.
Concept 3 of 3: Literacy, age and infant mortality
Behind each headline number is an exact definition, and CDS tests the definition rather than the number. Who counts as literate? Infant deaths out of what? Learn the wording the Census uses; the wrong options change just one word of it.
Definition
- Literate (Census 2011): a person aged seven or more who can both read and write with understanding in any language. Someone who can read but not write is not literate.
- Infant mortality rate (IMR): the number of deaths of infants under one year of age per 1,000 live births in a year.
- Adolescents (aged 10 to 19) were about one-fifth of India's people in 2011, a youthful group with high potential.
- India is a young country: its median age is about 28 years (UN estimate for the early 2020s), far below that of China, Japan or Europe.
- India had more males than females: the sex ratio was 943 females per 1,000 males in 2011.
| Measure | Meaning or 2011 value |
|---|---|
| Literate | Aged 7 or more; reads and writes with understanding in any language |
| Literacy rate (2011) | 74 per cent: males 82 per cent, females 65 per cent |
| Infant mortality rate | Deaths under one year of age per 1,000 live births in a yearQ CDS 2026 (I): the correct definition of IMR. |
| Adolescents (10 to 19) | About one-fifth of the populationQ CDS 2021 (II): a youthful population with high potential, not half the population. |
| Median age | About 28 years (early 2020s)Q |
| Sex ratio (2011) | 943 females per 1,000 males |
Practice this conceptself-check · 4 quick reps
The same idea in a real exam question:
CDS · 2023 · CDS (I) 2023 — General Knowledge · Q18Moderate
Example 3 · Indian Geography — Economy, Resources and Transport · Population Size and Growth
According to the Census 2011, which of the following statements is/are correct?
1. A person who can only read but cannot write, is not literate.
2. A person aged seven years and above, who can both read and write with understanding in any language is treated as literate.
Select the correct answer using the code given below.
Reading alone is not literacy
The Census counts a person as literate only if they can both read and write with understanding. A person who can only read is not literate.
IMR is a rate, not a count
IMR is infant deaths per 1,000 live births. A bare number of infant deaths in a year, or births per woman (that is the fertility rate), is a different measure.
One-fifth, and more boys
Adolescents were about one-fifth of India's people in 2011, not half. And as in the whole population, males outnumber females in this age group.
Summary — formulas & gotchas at a glance
A revision cheat-sheet for the formulas and gotchas above. Click any concept name to jump back to its full explanation.
Reference tables (3)
State populations and density5 rows
| States compared | Census 2011 figures |
|---|---|
| Kerala, Jharkhand, Assam, Punjab (population) | 3.34 crore, 3.30 crore, 3.12 crore, 2.77 croreQ CDS 2016 (II): Kerala, Jharkhand, Assam, Punjab is the decreasing order. |
| Meghalaya, Goa, Mizoram, Sikkim (population) | 29.7 lakh, 14.6 lakh, 10.9 lakh, 6.1 lakhQ CDS 2019 (I): Meghalaya is the most populous of these four. |
| Arunachal, Mizoram, Sikkim, Himachal (density) | 17, 52, 86, 123 per sq kmQ CDS 2018 (II): this is the ascending order of density. |
| Assam, Meghalaya, Nagaland, Arunachal (density) | 398, 132, 119, 17 per sq km |
| Bihar and Arunachal Pradesh (density) | 1,106 (highest) and 17 (lowest) per sq km |
Phases of population growth4 rows
| Period | Phase |
|---|---|
| 1901 to 1921 | Stagnant or stationary growth |
| 1921 to 1951 | Steady growth |
| 1951 to 1981 | Population explosion; peak growth of about 24.8 per cent in 1961 to 1971Q CDS 2020 (II): decadal growth was highest in the Census year 1971. |
| 1981 onwards | Growth still high but steadily slowing |
Literacy, age and infant mortality6 rows
| Measure | Meaning or 2011 value |
|---|---|
| Literate | Aged 7 or more; reads and writes with understanding in any language |
| Literacy rate (2011) | 74 per cent: males 82 per cent, females 65 per cent |
| Infant mortality rate | Deaths under one year of age per 1,000 live births in a yearQ CDS 2026 (I): the correct definition of IMR. |
| Adolescents (10 to 19) | About one-fifth of the populationQ CDS 2021 (II): a youthful population with high potential, not half the population. |
| Median age | About 28 years (early 2020s)Q |
| Sex ratio (2011) | 943 females per 1,000 males |
Watch out for (7)
- Kerala just beats Jharkhand→ State populations and density
- Large is not dense→ State populations and density
- A Census year names the decade that ends→ Phases of population growth
- Steady is not explosive→ Phases of population growth
- Reading alone is not literacy→ Literacy, age and infant mortality
- IMR is a rate, not a count→ Literacy, age and infant mortality
- One-fifth, and more boys→ Literacy, age and infant mortality
Test yourself on Indian Geography — Economy, Resources and Transport
20 past CDS questions from this chapter, timed at 20 minutes and marked the way the exam marks it. You see your score and every answer the moment you finish. Free to start.