4121: Which one of the following is used for dating archaeological specimens in wood, bones and shells?
(a) Uranium-238
(b) Argon isotope
(c) Carbon-14
(d) Strontium-90
4122: Which one of the following types of coal contains a higher percentage of carbon than the rest ?
(a) Bituminous coal
(b) Lignite
(c) Peat
(d) Anthracite
4123: With reference to the invaders in ancient India, which one of the following is the correct chronological order ?
(a) Greeks - Sakas - Kushans
(b) Greeks - Kushans - Sakas
(c) Sakas - Greeks - Kushans
(d) Sakas - Kushans - Greeks
4124: Consider the following Pairs : Wetlands Confluence of rivers
1. Harike Wetlands : Confluence of Beas and Satluj/Sutlej
2. Keoladeo Ghana : Confluence of National Park Banas and Chambal
3. Kolleru Lake : Confluence of Musi and Krishna
Which of the above pairs is/are correctly matched?
(a) 1 only
(b) 2 and 3
(c) 1 and 3
(d) 1, 2 and 3
4125: Consider the following:-
1. Carbon dioxide
2. Oxides of Nitrogen
3. Oxides of Sulphur
Which of the above is/are the emission/emissions from coal combustion at thermal power plants?
(a) 1 only
(b) 1 and 3 only
(c) 2 and 3 only
(d) 1, 2 and 3