CBSE Class 9 Social Science Population NCERT Solutions

(i) The correct option is (b) Both the area of departure and arrival. Migration involves people moving from one place to another. This movement decreases the population in the area they leave (departure) and increases the population in the area they move to (arrival). It also affects the distribution and composition (like age, sex ratio, skills) of the population in both areas.

(ii) The correct option is (a) High birth rates. When the birth rate is high, more children are born relative to the total population. This naturally leads to a larger proportion of children (typically defined as those under 15 years of age) in the population structure.

(iii) The correct option is (b) The number of persons added each year. The magnitude of population growth refers to the absolute increase in population over a specific period, usually a year. It is the difference between the total population at the end of the period and the total population at the beginning. The rate of growth, on the other hand, is the percentage increase.

(iv) The correct option is (c) Is 7 years old and can read and write any language with understanding. The Census of India, as per the 2001 data, defines a literate person as someone aged seven years and above who can both read and write with understanding in any one language. Simply being able to write one's name is not sufficient for this definition.

1. The rate of population growth in India has been declining since 1981 primarily due to the successful implementation and increasing awareness of family planning programs. These programs emphasize the benefits of adopting a smaller family size, which has led to a reduction in the birth rate over the years.
2. The major components that determine population growth are the birth rate, the death rate, and migration. Population increases when the birth rate exceeds the death rate, and when immigration (people entering a country) is greater than emigration (people leaving a country). Conversely, population decreases if the death rate is higher than the birth rate, or if emigration exceeds immigration.
3. Age Structure: This refers to the distribution of a population into various age groups. Typically, these groups are children (aged 0-14 years), the working-age population (aged 15-59 years), and the aged population (aged 60 years and above). The relative proportion of these groups significantly impacts a society's social and economic characteristics.

   $$Age\; Structure\; =\; \backslash text\{Percentage\; of\; population\; in\; different\; age\; groups\}$$

   Death Rate: The death rate is defined as the number of deaths occurring per 1,000 persons in a given area or country during a particular year.

   $$Death\; Rate\; =\; \backslash frac\{\backslash text\{Number\; of\; deaths\}\}\{\backslash text\{Total\; population\}\}\; \backslash times\; 1000$$

   Birth Rate: The birth rate is defined as the number of live births occurring per 1,000 persons in a given area or country during a particular year.

   $$Birth\; Rate\; =\; \backslash frac\{\backslash text\{Number\; of\; live\; births\}\}\{\backslash text\{Total\; population\}\}\; \backslash times\; 1000$$

4. Migration is a significant determinant of population change because it directly alters the number and composition of the population in both the place of origin and the place of destination.

   Internal Migration: When people move within a country (e.g., from rural to urban areas), the total population of the country remains the same, but the population distribution and density change. For instance, rural areas may experience a decrease in population, while urban areas see an increase, potentially leading to changes in the age and sex composition of both.

   International Migration: When people move between countries, it directly affects the population size of both the sending and receiving countries. If more people immigrate into a country than emigrate from it, the country's population grows. Conversely, if emigration exceeds immigration, the population declines.