Explanation: Population density is a critical demographic measure that indicates the number of people living per unit area, typically expressed as the number of people per square kilometer. This measure is essential for understanding the distribution of human populations across different regions and can influence various socio-economic factors such as resource allocation, infrastructure development, and environmental impact.
Arunachal Pradesh, located in the northeastern part of India, is characterized by its vast, sparsely populated areas. The state is known for its extensive forest cover, mountainous terrain, and numerous rivers. These geographical features contribute to its low population density. The state's total area is approximately 83,743 square kilometers, but its population is relatively small compared to its land area, leading to a low population density.
In contrast, the other options provided have different characteristics that result in higher population densities:
- **Bihar**: This state has a large population and a relatively smaller land area, leading to a high population density. The state's population is concentrated in urban and semi-urban areas, contributing to its high density.
- **Punjab**: Known for its agricultural productivity, Punjab has a significant population concentrated in its fertile plains. The state's smaller land area compared to its population results in a moderate to high population density.
- **Goa**: Despite being a small state, Goa has a relatively high population density due to its urbanization and tourism industry. The state's small land area and significant population make it denser than Arunachal Pradesh.
Understanding population density is crucial for planning and policy-making, as it helps in assessing the need for resources, infrastructure, and services in different regions. Arunachal Pradesh's low population density reflects its unique geographical and demographic characteristics, making it stand out among the given options.
In summary, Arunachal Pradesh has the lowest population density among the given options due to its vast, sparsely populated areas, extensive forest cover, and mountainous terrain. This characteristic is a result of the state's large land area relative to its population, making it the correct answer to the question.