656: If there were no organic life on the Earth, the amount of oxygen in the atmosphere will:
(a) Remain unchanged.
(b) Be approximately hundred per cent.
(c) Be almost nil.
(d) Be approximately fifty per cent.
657: The evidence for the rotation of stars comes mainly from the
(a) Doppler effect
(b) Photoelectric effect
(c) Stark effect
(d) Zeeman effect
658: Rolling Plan can be best defined in context of India as:
(a) Formulation of annual plans
(b) Perspective of Five-Year Plan with the provision of extending by one year at a time so that there would be a constant planning horizon of five years
(c) Aims and achievements reviewed every year in a Five-Year Plan
(d) Plan for full 5 years
659: Due to some reasons, if there is a huge fall in the population of species of butterflies, what could be its likely consequence/consequences?
1. Pollination of some plants could be adversely affected.
2. There could be a drastic increase in the fungal infections of some cultivated plants.
3. It could lead to a fall in the population of some species of wasps, spiders and birds.
Select the correct answer using the code given below:
(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
660: If the angles of a triangle are in the ratio of 4 : 3 : 2, then the triangle
(a) is obtuse
(b) has one angle greater than 80°
(c) is a right triangle
(d) is acute