By what majority decision did the Supreme Court constitution bench dismiss the election petition in the case of P.A. Sangma v. Pranab Mukherjee?

Which of the following landmark cases of the Supreme Court of India involved the second-largest bench (consisting of 11 judges) in constitutional history?

In which landmark case did the Supreme Court strike down the Illegal Migrants (Determination by Tribunal) Act, 1983, as unconstitutional on the grounds that it violated the Centre's duty under Article 355?