Population density is closely related to physical and socio-economic factors-

Dense population in UP, West Bengal, Bihar, Punjab, Haryana, Kerala is due to flat and fertile plains, favourable climate, water availability and socio-economic factors.

Moderate density is seen in Odisha, Assam, Gujarat, Andhra Pradesh, Tamil Nadu etc. due to possibilities of agriculture, industrial development and favourable climate to some extent.

Sparse population of Jammu & Kashmir, Himachal Pradesh, Arunachal Pradesh, Sikkim, North-East States is due to hilly terrain, dense forests and harsh climate. Rajasthan has water shortage and its hot & dry climate accounts for low population density.

 Favourable factors for Transport network, industrialization, urbanization in Maharashtra, Goa, Delhi NCR etc. account for high population density.