Population
People are a nation's most important resource. This Class 9 Geography chapter examines India's population size and distribution, density, growth and its causes, and key features such as age composition, sex ratio and literacy.
Learning objectives
- Describe India's population size and distribution.
- Explain population density and growth.
- Understand the processes of population change.
- Learn about age, sex ratio and literacy.
Key concepts
Size, distribution and density
India has a very large population, the result of which is uneven distribution: some regions, like the fertile northern plains, are densely populated, while mountains, deserts and forests are thinly peopled. Population density is the number of people living per square kilometre. It is found by dividing the total population of an area by its area.
Population growth and its processes
Population growth means the change in the number of people over time. It is affected by three processes: the birth rate (births per thousand people in a year), the death rate (deaths per thousand), and migration (movement of people into or out of an area). When the birth rate is much higher than the death rate, the population grows quickly.
Age and sex composition
The population can be divided by age into children, working-age adults, and the elderly; the proportion of each affects a country's needs and workforce. The sex ratio is the number of females per thousand males. A balanced sex ratio is important, and an unfavourable ratio points to social problems such as the neglect of girls.
Literacy and population policy
Literacy — the ability to read and write — is an important measure of a population's quality, and India has worked to raise its literacy rate, especially among women. To manage population growth and improve people's lives, India adopted a National Population Policy, which encourages family welfare, education and the health of adolescents and mothers.
Important formulas
Population density
Population density = total population ÷ total area (persons per sq km)
Key definitions
- Population density
- The number of people living per square kilometre.
- Birth rate
- The number of live births per thousand people in a year.
- Migration
- The movement of people into or out of an area.
- Sex ratio
- The number of females per thousand males in a population.
Solved examples
Q1. How is population density calculated?
Solution: By dividing the total population of an area by its area.
Q2. Name the three processes of population change.
Solution: Birth rate, death rate and migration.
Q3. What does the sex ratio measure?
Solution: The number of females per thousand males.
Common mistakes to avoid
- Confusing population size with population density.
- Forgetting migration as a process of population change.
- Mixing up birth rate and death rate.
- Defining sex ratio the wrong way (it is females per 1000 males in India's usage).
Population — MCQ Quiz
10 questions with instant feedback. Use number keys 1–4 to answer.
Population density is the number of people per:
Practice questions
Short answer
What is population density?
The number of people living per square kilometre.
What are the three processes of population change?
Birth rate, death rate and migration.
What is the sex ratio?
The number of females per thousand males.
Long answer
Explain the processes that bring about change in population.
The size of a population changes through three main processes. The first is the birth rate, the number of live births per thousand people in a year; a high birth rate increases the population. The second is the death rate, the number of deaths per thousand people in a year; when the death rate falls, for example because of better healthcare, the population grows. The difference between the birth rate and the death rate is the natural increase of population. The third process is migration, the movement of people into or out of an area. People moving into a region add to its population, while those moving out reduce it. In India, the rapid growth of population over the years has been mainly due to the birth rate remaining higher than the death rate, while migration affects the distribution of people between regions.
Why are features like sex ratio and literacy important indicators of a population?
Features such as the sex ratio and literacy are important because they reveal the quality and condition of a population, not just its size. The sex ratio, the number of females per thousand males, shows the balance between men and women; a low or unfavourable sex ratio is a warning sign of social problems like the neglect or discrimination against girls, and a balanced ratio is important for a healthy society. Literacy, the ability to read and write, is a key measure of a population's development, since an educated population is better able to find good work, take care of health, and participate in the life of the country. Raising literacy, especially among women, improves families and the nation as a whole. That is why India tracks these indicators and, through its National Population Policy, works to improve education, the welfare of girls and women, and the health of adolescents and mothers.
HOTS (Higher Order Thinking)
Why is a balanced sex ratio important for society?
Because a serious imbalance signals discrimination against girls and creates social problems, while a balanced ratio reflects fair treatment and a healthier society.
How does improving literacy help control population growth?
Educated people, especially women, tend to make better-informed choices about family size and health, which helps slow rapid population growth.
Quick revision
Revision notes
- India has a large, unevenly distributed population (dense plains, sparse mountains/deserts).
- Density = total population ÷ area (persons per sq km).
- Change processes: birth rate, death rate, migration; high birth>death → rapid growth.
- Sex ratio = females per 1000 males; literacy = ability to read/write; National Population Policy.
Key takeaways
- Density measures people per square kilometre.
- Birth rate, death rate and migration change population.
- Sex ratio and literacy show population quality.
Frequently asked questions
How is population density found?
By dividing the total population by the area.
What changes a population's size?
Birth rate, death rate and migration.
What is the sex ratio?
The number of females per thousand males.