Mormugao, one of the major ports of India, lies at the mouth of which river?

The correct answer is C, 30 May 1987. On that day the Goa, Daman and Diu Reorganisation Act of 1987 came into force, Goa became the twenty-fifth state of the Union, and Daman and Diu continued as a separate union territory; 30 May is kept as Goa Statehood Day. Option A, 19 December 1961, is the day Portuguese rule ended and is Goa Liberation Day, but Goa then became a union territory, not a state. Option B, 16 January 1967, is the day of the Goa Opinion Poll, in which Goans voted against merging with Maharashtra; it decided Goa's separate identity but gave it no statehood. Option D, 18 June 1946, is Goa Revolution Day, marking Dr Ram Manohar Lohia's defiance of the Portuguese ban on public meetings at Margao. Keep the four dates in order: 1946, 1961, 1967 and 1987.

The correct answer is B, Operation Vijay. Indian air, land and naval forces moved into Goa, Daman and Diu from 17 to 19 December 1961 in Operation Vijay, and 19 December is observed as Goa Liberation Day. The name is also carried by the Kargil operation of 1999, which is the trap in this question, so read the year in the stem. Option A, Operation Polo, was the police action of September 1948 by which Hyderabad was integrated into India. Option C, Operation Meghdoot, was the occupation of the Siachen glacier in 1984. Option D, Operation Cactus, was the Indian intervention in the Maldives in 1988 to put down a coup attempt. All four are real Indian operations, which is why only the date and the place fix the answer.

The correct answer is D, the Mandovi. Panaji, also called Panjim, stands on the left bank of the Mandovi, known in Goa as the Mhadei, near the point where the river meets the Arabian Sea; Old Goa lies a short way upstream on the same river. Option A, the Zuari, is wrong although it is the largest river of the state; Mormugao port and the town of Vasco da Gama lie at its mouth, not the capital. Option B, the Terekhol, is wrong; it is the small river on the northern border with Maharashtra, with the Terekhol fort at its mouth. Option C, the Sal, is wrong; it is a short river in South Goa near Mobor and Betul. Remember also that the Dudhsagar Falls are on the Mandovi and that the Cumbarjua canal joins the Mandovi to the Zuari.

The correct answer is B, Mollem National Park. It is the single national park of Goa and lies within the Bhagwan Mahavir Wildlife Sanctuary on the border with Karnataka, in the belt of the Western Ghats where the Dudhsagar Falls also stand. Options A, C and D name real protected areas of Goa, but all three are wildlife sanctuaries and not national parks: Bondla is the small sanctuary near Ponda with a well known zoo and botanical garden, Cotigao lies in the far south near Canacona, and Netravali is in the Sanguem taluka, famous for its bubbling springs. The state's other protected area is the Dr Salim Ali Bird Sanctuary on Chorao island in the Mandovi. Examiners test the difference between a national park and a sanctuary, so fix Mollem as the only park.

The correct answer is A, the Mandovi. The Dudhsagar Falls, a drop of roughly 310 metres in four tiers, are on the Mandovi river in the Western Ghats near the Goa and Karnataka border, inside the Bhagwan Mahavir Wildlife Sanctuary; the name means sea of milk, from the white sheet the water makes in the monsoon. Option B, the Zuari, is wrong although it is the largest river of the state and carries Mormugao port at its mouth. Option C, the Sal, is wrong; it is a small river of South Goa with no such fall. Option D, the Chapora, is wrong; it is a northern river with a Portuguese fort at its mouth. Note that the same river, the Mandovi, carries the capital Panaji, which makes it the single most examinable river of Goa.