136: Consider the following statements :
At the present level of technology available in India, solar energy can be conveniently used to
I. supply hot water to residential buildings.
II. supply water for minor irrigation projects.
III. provide street lighting.
IV. electrify a cluster of villages and small towns.
Of these statements
(a) I, II, III and IV are correct.
(b) II and IV are correct
(c) I and III are correct
(d) I, II and III are correct
137: Which one of the following statements is correct with reference to our solar system ?
(a) The Earth is the densest of all the planets in our solar system
(b) The predominant element in the composition of Earth is silicon
(c) The Sun contains 75 per cent of the mass of the solar system
(d) The diameter of the Sun is 190 times that of the Earth
138: The President of Union of India has the same constitutional authority as the:
(a) British Monarch
(b) President of U.S.A.
(c) President of Egypt
(d) President of Russia
139: With reference to the food chains in ecosystems, which of the following kinds of organism is / are known as decomposer organism / organisms?
1. Virus
2. Fungi
3. Bacteria
Select the correct answer using the codes given below.
(a) 1 only
(b) 1 and 3 only
(c) 2 and 3 only
(d) 1, 2 and 3
140: Unemployment which occurs when workers move from one job to another job is known as
(a) Seasonal unemployment
(b) Frictional unemployment
(c) Technological unemployment
(d) Cyclical unemployment