Which of the following statement is/are NOT correct in respect of population growth in the decade 1951-1981?

The decades 1951-1981 are referred to as the period of population implosion in India

The correct answer is option 2: The decades 1951-1981 are referred to as the period of population implosion in India.

Statement 1 : “The decades 1951-1981 are referred to as the period of population explosion in India.” — Correct. During this period, India experienced a very rapid increase in population. 

Statement 2 : “The decades 1951-1981 are referred to as the period of population implosion in India.” — Incorrect. The correct term is population explosion, not implosion.

Statement 3 : “There was a rapid fall in the mortality rate but a high fertility rate of population in the country.” — Correct. This was the main reason for rapid population growth during this period.

NCERT: "The decades 1951-1981 are referred to as the period of population explosion in India, which was caused by a rapid fall in the mortality rate but a high fertility rate of population in the country. The average annual growth rate was as high as 2.2 per cent. It is in this period, after the Independence, that developmental activities were introduced through a centralised planning process and economy started showing up ensuring the improvement of living condition of people at large. Consequently, there was a high natural increase and higher growth rate. Besides, increased international migration bringing in Tibetans, Bangladeshis, Nepalies and even people from Pakistan contributed to the high growth rate."