During which decade did the population of India register a negative decadal growth rate?

Introduction / Context:
India's population has generally shown positive growth from census to census. However, there was one decade in the twentieth century when the decadal growth rate was negative, meaning that the population at the end of the decade was lower than at its beginning. This question tests your knowledge of demographic history and the specific decade in which India recorded negative population growth, largely due to epidemics, famines, and the impact of World War.

Given Data / Assumptions:

• The question concerns decadal population growth of India.
• We need the decade with negative growth.
• Four decade ranges from 1911 to 1951 are given.
• We assume census based official records of population.

Concept / Approach:
According to census data, the decade from 1911 to 1921 is known as the period of negative population growth in India. This was due to reasons such as the influenza pandemic of 1918, high mortality, and other adverse conditions. The census of 1921 showed a decline compared to 1911 figures, so demographers call 1921 the demographic divide and mark 1911–1921 as the only decade with negative growth. All later decades show positive growth though at varying rates.

Step-by-Step Solution:
Step 1: Recall that 1921 is called the demographic divide in Indian population studies. Step 2: Understand that the decade leading up to the 1921 census, that is 1911–1921, recorded a small decline in population. Step 3: Recognise that later decades like 1921–1931 and 1931–1941 show positive growth rates. Step 4: Among the options, identify 1911–1921 as the decade with negative growth. Step 5: Choose 1911–1921 as the correct answer.

Verification / Alternative check:
Demography chapters in geography and economics textbooks contain tables of decadal growth rates based on census data. These tables clearly show a negative growth rate for 1911–1921 and positive rates for all other decades. The 1921 census is often described as unique because it is the only one in which the total population actually fell compared with the previous census. Checking these tables in multiple sources such as government publications, yearbooks, or competitive exam guides will confirm that 1911–1921 is the only decade with negative population growth.

Why Other Options Are Wrong:
1921–1931: Marks a return to positive growth after the demographic divide, not a negative decade.
1941–1951: This decade covers the period around independence and shows population increase, not decline.
1931–1941: Also shows positive growth, though affected by economic and political conditions.

Common Pitfalls:
A frequent error is to confuse the year 1921 being special with later decades such as 1921–1931. Some candidates also assume that war time periods like 1941–1951 might show negative growth due to World War and partition, but census data do not support this. To avoid such mistakes, remember the key phrase demographic divide and link it specifically with the 1921 census and the preceding decade 1911–1921. Visualising the census table once during revision is a good way to fix this in memory.

Final Answer:
India recorded a negative decadal population growth rate during the decade 1911–1921.