Population, Census 2011 and Composition

Why Population Is a Scoring Topic

The Census of India is the largest administrative exercise on Earth and the single most reliable source of population data for the country. The 2011 Census was the 15th National Census since 1872 and the 7th after Independence. The decennial census is conducted under the Census Act of 1948 and is a Union subject, which means it is carried out by the central government through the Registrar General and Census Commissioner of India. Because the figures are fixed and frequently asked, this is a high-return, low-effort chapter for CDS/OTA aspirants.

Examiners like population questions because they test factual recall: a single line memorised correctly fetches a full mark with zero working. There is no lengthy reasoning, no diagram and no multi-step calculation involved — you either know the figure or you do not. Spend a focused hour here and you protect three to four marks in every General Studies paper, and these are among the safest marks in the entire syllabus because the data does not change between attempts.

Population also links neatly to other parts of the GS paper — economics (workforce, unemployment), polity (delimitation of constituencies based on population) and current affairs (welfare schemes for girls and the elderly). Mastering the core numbers therefore pays off well beyond a single question.

Core Terms You Must Define

Before the numbers, fix the vocabulary. CDS often asks for the definition itself, not just the value, so understanding each term precisely matters as much as memorising figures.

• Population density: the number of persons living per square kilometre of land. It tells us how crowded a region is and is also called the arithmetic density.
• Sex ratio: the number of females per 1000 males in a population. It reflects social attitudes, female survival and migration patterns.
• Child sex ratio: females per 1000 males in the age group 0–6 years. A falling child sex ratio is an early warning of sex-selective practices.
• Literacy rate: the percentage of people aged 7 years and above who can read and write with understanding in any language. Merely signing one's name does not count.
• Growth rate: the change in population over a decade, expressed as a percentage. This is the decadal growth, distinct from the annual growth rate.
• Birth rate and death rate: the number of live births and deaths per 1000 people in a year. The difference between them (minus migration) gives the natural growth of population.

Population change in any region is governed by three processes: births, deaths and migration. When births exceed deaths, the population grows naturally; migration then adds or subtracts people on top of this natural change. Keeping these drivers clear helps you answer conceptual questions, not just numerical ones.

The Headline 2011 Figures

These are the numbers most likely to appear. Learn them as a block.

• Total population: about 121 crore (1.21 billion).
• Population density: 382 persons per km² (up from 325 in 2001).
• Sex ratio: 943 females per 1000 males.
• Child sex ratio (0–6): 919 — a fall from 927 in 2001, which worried policymakers.
• Literacy rate: 74.04% overall (male about 82%, female about 65%).
• Decadal growth (2001–2011): 17.7%.

Uneven Distribution Across India

India's people are spread very unevenly. Just over half the population lives in five states: Uttar Pradesh, Maharashtra, Bihar, West Bengal and Andhra Pradesh. At the other extreme, the entire north-eastern region and the hill states together hold only a small fraction of the total. This lopsided spread is one of the defining features of Indian human geography.

• Most populous state: Uttar Pradesh.
• Least populous state: Sikkim.
• Most populous Union Territory: Delhi.
• Least populous UT (2011): Lakshadweep.

What drives the pattern?

Three sets of factors decide where people settle. Physical factors include terrain, climate, availability of water and soil fertility — people avoid rugged mountains, arid deserts and waterlogged swamps. Economic factors such as industries, mineral deposits, transport and urbanisation pull people towards cities and industrial belts. Social and cultural factors — historic settlement, religious centres and cultural attachment to a place — explain why some old towns remain crowded.

Fertile river plains such as the Ganga basin are densely peopled because they offer water, level land and rich alluvial soil for farming. By contrast, the Thar desert of Rajasthan, the dense forests of the central plateau and the snowy Himalayan heights remain sparsely populated. Urbanisation adds a fresh layer: cities like Mumbai, Delhi and Kolkata draw migrants in search of jobs, raising local density far above the surrounding countryside.

Density: Highest and Lowest

Density numbers are pure recall and appear almost every year in some form.

• Highest density among states: Bihar (about 1106 persons per km²).
• Lowest density among states: Arunachal Pradesh (about 17 persons per km²).
• Highest density overall: the National Capital Territory of Delhi.

Sex Ratio and Its State Extremes

The all-India sex ratio of 943 improved slightly from 933 in 2001, but it still hides sharp regional differences. Knowing the extremes is enough for most questions.

• Highest sex ratio (state): Kerala, around 1084 females per 1000 males — the only major state with more women than men.
• Lowest sex ratio (state): Haryana, around 879.
• Highest sex ratio (UT): Puducherry.
• Lowest sex ratio (UT): Daman and Diu (skewed by migrant male workers).

Why does Kerala lead? Higher female literacy, better health care and strong social development have supported the survival and status of women there. In contrast, states with strong son-preference and economic activity that attracts male migrants show lower ratios. Daman and Diu's very low figure is a good example of how a flood of male industrial workers can distort the count.

Literacy: National and State Picture

Literacy rose from 64.8% in 2001 to 74.04% in 2011 — a jump of nearly ten percentage points in a single decade. The gender gap is the key talking point: male literacy (about 82%) clearly exceeds female literacy (about 65%), although the gap is slowly closing.

• Most literate state: Kerala (about 94%).
• Least literate state: Bihar (about 62%).
• Most literate UT: Lakshadweep.
• The 2001–2011 decade narrowed the male–female gap, as female literacy grew faster than male literacy.

Literacy is one of the best indicators of social development because it links directly to health, income and women's empowerment. States that invested early in schooling and public health, like Kerala, top the table, while states with weaker school access and higher poverty lag behind. The faster growth of female literacy is an encouraging sign that the gender divide in education is shrinking.

Growth, Age Structure and Dependency

India's decadal growth slowed from 21.5% (1991–2001) to 17.7% (2001–2011), an early sign of demographic transition. Yet the population is still young.

Working age and dependency

• Working-age group: 15–59 years — the productive population.
• Dependent groups: children (0–14) and the elderly (60+).
• Dependency ratio: the ratio of dependents to the working-age population. A low ratio means a larger workforce relative to dependents.

Demographic dividend

Because a large share of Indians are entering working age, the country enjoys a demographic dividend — a potential boost to growth if these people get jobs, education and skills. The age–sex pyramid for India is broad-based, narrowing towards the top, which is typical of a young and still-growing population. Developed countries, by contrast, have pyramids that bulge in the middle and top, reflecting older populations.

Demographic transition

India is passing through the demographic transition — the shift from high birth and death rates to low birth and death rates as a country develops. Death rates fell first thanks to better medicine and food, while birth rates have fallen more slowly, which is why the population kept rising even as growth began to slow. The slowing decadal growth from 21.5% to 17.7% is direct evidence of this transition in progress.

Worked Example: Density and Sex Ratio

Common Mistakes to Avoid

• Writing sex ratio as males per 1000 females — it is always females per 1000 males.
• Mixing up 2001 and 2011 figures; for the exam, anchor on 2011 values.
• Assuming the most populous state also has the highest density (it does not).
• Forgetting that literacy counts only the 7+ age group.
• Confusing child sex ratio (0–6) with the overall sex ratio — they have different values and trends.

Previous-Year Style Practice

Notice how the question hinges on the words “state” and “density”. Read CDS options carefully — a single qualifier (state vs UT, populous vs dense) usually decides the correct answer.

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