Sikkim became an Associate State of the Indian Union through

Sikkim became an Associate State of the Indian Union through

the Constitution (36th Amendment) Act, 1975
the Constitution (7th Amendment) Act, 1956
the Constitution (35th Amendment) Act, 1974
the Constitution (5th Amendment) Act, 1955
This question was previously asked in
UPSC CAPF – 2018
The correct answer is C) the Constitution (35th Amendment) Act, 1974.
The 35th Amendment Act, 1974, amended the Constitution to provide for Sikkim’s association with the Indian Union. It introduced a new Article 2A and the Tenth Schedule to the Constitution, laying down the terms and conditions of Sikkim’s association. This gave Sikkim the status of an ‘Associate State’.
Subsequently, the 36th Amendment Act, 1975, fully integrated Sikkim into India by making it the 22nd state of the Indian Union. This amendment repealed Article 2A and the Tenth Schedule inserted by the 35th Amendment and made necessary amendments to the First and Fourth Schedules and introduced Article 371F. The 7th Amendment Act, 1956, was related to the reorganization of states on a linguistic basis.