Answer: The distribution of India's population is affected by physical, economic and social factors.
- Relief: the northern plains and coastal plains are level and fertile and are densely populated; the Himalayas and other hilly and mountainous areas are thinly populated because of rugged terrain, little cultivable land, cold climate and poor accessibility.
- Climate and rainfall: areas with moderate climate and good rainfall (Ganga plains, Kerala, the east coast) are densely populated; the desert of Rajasthan and rain-shadow areas are sparsely populated.
- Soil and water: fertile alluvial and black soils and availability of water from rivers, lakes and canals support agriculture and large populations; dry areas like the Thar desert lack water.
- Industries, mining and transport: industrial cities such as Mumbai, Kolkata, Delhi and Chennai and mining areas of Jharkhand and Odisha attract people.
- Social and other factors: urbanisation, education, health facilities, employment opportunities and migration also affect the distribution.