11: A consumer is said to be in equilibrium, if

(a) he is able to fulfil his need with a given level of income
(b) he is able to live in full comforts with a given level of income
(c) he can fulfil his needs without consumption of certain items
(d) he is able to locate new sources of income
12: In which of the following activities are Indian Remote Sensing (IRS) satellites used?

1. Assessment of crop productivity
2. Locating groundwater resources
3. Mineral exploration
4. Telecommunications
5. Traffic studies

Select the correct answer using the code given below.
(a) 1, 2 and 3 only
(b) 4 and 5 only
(c) 1 and 2 only
(d) 1, 2, 3, 4 and 5
13: How much is one barrel of oil approximately equal to?

(a) 131 litres
(b) 159 litres
(c) 257 litres
(d) 321 litres
14: With reference to the scientific progress of ancient India, which of the statements given below are correct?

1. Different kinds of specialized surgical instruments were in common use by 1st century AD.

2. Transplant of internal organs in the human body had begun by the beginning of 3rd century AD.

3. The concept of sine of an angle was known in 5th century AD.

4. The concept of cyclic quadrilaterals was known in 7th century AD.

Select the correct answer using the codes given below :

(a) 1 and 2 only
(b) 3 and 4 only
(c) 1, 3 and 4 only
(d) 1, 2, 3 and 4
15: Which of the following have coral reefs?

1. Andaman and Nicobar Islands
2. Gulf of Kachchh
3. Gulf of Mannar
4. Sunderbans

Select the correct answer using the code given below.

(a) 1, 2 and 3 only
(b) 2 and 4 only
(c) 1 and 3 only
(d) 1, 2, 3 and 4