National Mathematics Day is observed on 22 December to mark the birth anniversary of which mathematician?

The correct answer is A, 28 February. On this day in 1928 C. V. Raman announced the discovery of the Raman Effect, the scattering of light with a changed wavelength when it passes through a transparent medium, and the discovery brought him the Nobel Prize in Physics in 1930. The day has been kept every year since 1987 on a fresh theme decided by the Government. Option B is wrong because 11 May is National Technology Day, kept for the Pokhran-II tests of 1998. Option C is wrong because 22 December is National Mathematics Day, the birth anniversary of Srinivasa Ramanujan. Option D is wrong because 15 September is Engineers' Day, the birth anniversary of Sir M. Visvesvaraya. Papers put all four national days in one question, so read which field is named before choosing.

The correct answer is B, the announcement of the Raman Effect. C. V. Raman made the announcement on 28 February 1928 and won the Nobel Prize in Physics for it in 1930, the first Nobel in the sciences for an Indian. Option A is wrong because Aryabhata, India's first satellite, was launched on 19 April 1975 with Soviet help, and that date carries no national day. Option C is wrong because the founding of the Council of Scientific and Industrial Research is not the reason for this observance, although the Council takes part in the celebrations. Option D is wrong because the first test flight of the Hansa-3 trainer aircraft belongs to 11 May 1998 and is one of the three achievements behind National Technology Day.

The correct answer is B, the nuclear tests carried out at Pokhran. On 11 May 1998 India tested nuclear devices at Pokhran in Rajasthan under Operation Shakti; the same day the indigenous Hansa-3 trainer aircraft made its first test flight and the Trishul missile was successfully test-fired, and Prime Minister Atal Bihari Vajpayee named the date National Technology Day. It was observed for the first time in 1999. Option A is wrong because the Light Combat Aircraft Tejas made its maiden flight in January 2001. Option C is wrong because the first Indian remote sensing satellite, IRS-1A, was launched in 1988 and is not connected with this day. Option D is wrong because the PARAM series of supercomputers was developed by C-DAC through the 1990s, again with no link to this date.

The correct answer is B, Dr Sarvepalli Radhakrishnan. Radhakrishnan, a philosopher and teacher who became the first Vice-President and the second President of India, was born on 5 September 1888; when his students wished to celebrate his birthday he asked that the day be kept for teachers instead. Option A is wrong because Maulana Abul Kalam Azad was born on 11 November, which is National Education Day. Option C is wrong because Swami Vivekananda was born on 12 January, observed as National Youth Day. Option D is wrong because Dr Zakir Husain, the third President of India and an educationist, has no national day in his name. Remember also that World Teachers' Day, a UNESCO observance, falls a month later on 5 October. Examiners also like to ask who requested that the day be kept for teachers, and the answer is Radhakrishnan himself.

The correct answer is B, Maulana Abul Kalam Azad. Azad was born on 11 November 1888 and became independent India's first Minister of Education; the first Indian Institutes of Technology, the University Grants Commission and the All India Council for Technical Education belong to his term, and the Ministry declared his birthday National Education Day in 2008. Option A is wrong because Radhakrishnan's birthday, 5 September, is Teachers' Day. Option C is wrong because Jyotirao Phule, who with Savitribai Phule opened schools for girls and for the depressed classes, is remembered on his own birth anniversary in April but not by a national education day. Option D is wrong because Madan Mohan Malaviya founded Banaras Hindu University and is remembered on 25 December, kept as Good Governance Day.