Explanation:

The Fundamental Duties were incorporated in Part IV-A of the Constitution by the Constitution 42nd Amendment Act, 1976, during the Emergency under Indira Gandhi’s government.

Today, there are 11 Fundamental Duties described under Article 51-A, of which 10 were introduced by the 42nd Amendment and the 11th was added by the 86th Amendment in 2002, during Atal Bihari Vajpayee’s government.

Source: Indian Polity by Laxmikanth