1. Human ear is most sensitive to noise in which of the following ranges:
(A) 20 Hz -20 KHz
(B) 100-500 Hz
(C) 10-12 KHz
(D) 13-16 KHz

2. Which one of the following units is used to measure intensity of noise?
(A) decibel
(B) Hz
(C) Phon
(D) Watts/m2

3. If the population growth follows a logistic curve, the maximum sustainable yield:
(A) is equal to half the carrying capacity.
(B) is equal to the carrying capacity.
(C) depends on growth rates.
(D) depends on the initial population.

4. Chemical weathering of rocks is largely dependent upon:
(A) high temperature
(B) strong wind action
(C) heavy rainfall
(D) glaciation

5. Structure of earth's system consists of the following:
Match List-I with List-II and give the correct answer.
List-I (Zone)                  List-II (Chemical Character)
(a) Atmosphere               (i) Inert gases
(b) Biosphere                 (ii) Salt, fresh water, snow and ice
(c) Hydrosphere            (iii) Organic substances, skeleton matter
(d) Lithosphere             (iv) Light silicates

(a)        (b)        (c)        (d)      
(A)       (ii)        (iii)       (i)         (iv)      
(B)       (i)         (iii)       (ii)        (iv)      
(c)        (ii)        (i)         (iii)       (iv)      
(D)       (iii)       (i)         (ii)        (iv)