Article 51A, which lists the Fundamental Duties, came into force on:

Article 51A was inserted into the Constitution by the 42nd Constitutional Amendment Act, 1976, and the provision on Fundamental Duties came into force on 3 January 1977.

Background:

• The 42nd Amendment was passed during the internal emergency of 1975 to 1977.
• It is often called a "mini-Constitution" because of the large number of changes it made.

It received the President's assent on 18 December 1976, and different sections were brought into force on different dates. The section inserting Part IVA took effect from 3 January 1977.

Other important changes by the 42nd Amendment:

• It added the words "socialist", "secular" and "integrity" to the Preamble.
• It added new Directive Principles, such as equal justice and free legal aid (Article 39A) and protection of the environment (Article 48A).
• It added Part XIVA on administrative tribunals.

Number of duties:

• Ten duties were added by the 42nd Amendment.
• An eleventh duty was added by the 86th Amendment Act, 2002, which came into force later.

Nature of Fundamental Duties:

• They are not enforceable by courts, but they remind citizens of their responsibilities.
• Many of them already existed in Indian tradition and were part of good citizenship.
• Courts may refer to them when judging whether a law that gives effect to a duty is reasonable.
• The 44th Amendment, passed after the emergency, reversed many changes of the 42nd Amendment, but it left the Fundamental Duties untouched.

Why not the other options?

• ✗18 December 1976 is the date of the President's assent to the Amendment, not the date the Article came into force.
• ✗Good to know
• ✗The other dates do not match the Amendment.