As per 2011 census, Which of the following States of India is most densely populated?

Bihar is the correct answer. In Census 2011, Bihar had a density of about 1,106 persons per sq km, the highest among all states. Delhi (about 11,320) is densest overall, but it is a Union Territory, so it is excluded when the question asks about states.

• West Bengal (about 1,028) is second among states but still below Bihar.
• Kerala (about 860) is densely populated for its size but ranks lower nationally.
• Uttar Pradesh (about 829) is the most populous state in absolute numbers, which is why aspirants confuse it with density. Population and density are different measures.

Core concept: density = population / area. Bihar's high density reflects a large population on a small land area with heavy dependence on agriculture, which links to the Mains theme of population pressure, migration and human development. Keep the state-wise census table handy, since questions often swap total population with density.

Trap: choosing Uttar Pradesh because it is the largest state by population. Density depends on area as well.