The correct option is 1 and 3 only.
Explanation
Federations are generally formed through two historical routes: "Coming Together" and "Holding Together." These routes determine the balance of power between the central authority and the constituent units.
Statement 1 is Correct: The "Coming Together" route involves independent states coming together on their own to form a bigger unit. Examples include the United States of America, Switzerland, and Australia.
Statement 2 is Incorrect: In a "Coming Together" federation, the constituent states usually have equal power and are strong vis-à-vis the federal government. The tendency for the central government to be more powerful vis-à-vis the states is a characteristic of "Holding Together" federations (e.g., India, Spain, Belgium), where a large country decides to divide its power between the constituent states and the national government.
Statement 3 is Correct: The primary objective of independent states forming a "Coming Together" federation is to increase their security by pooling sovereignty and retaining identity.
Key Takeaway: In "Coming Together" federations (USA, Australia), states retain significant autonomy and power. In "Holding Together" federations (India, Spain), the central government is generally more powerful than the states.