G.V. Mavalankar was indeed the first Speaker of the Lok Sabha. Dr. B.R. Ambedkar was the Chairman of the Drafting Committee, not the President of the Constituent Assembly. Dr. Rajendra Prasad was the President of the Constituent Assembly, not the Chairman of the Drafting Committee. Dr. Sachchidananda Sinha was the temporary Chairman of the Constituent Assembly during its first meeting, not the First Leader of the Opposition in Lok Sabha.