Environmental Science Questions and Answers - Physical Characteristic of Water Part-1

1. Logistic method is also called as _______
a) Arithmetical increase method
b) Geometrical increase method
c) Incremental increase method
d) Decreased rate of growth method

Answer: d
Explanation: Logistic method is also called a decreased rate of growth method. In this method, the percentage increase in growth rate and then the percentage decrease in growth rate are founded where all populations grow according to the logistic curve

2. Consider the following statements.
i. The arithmetical increase method is suitable for new cities
ii. The decreasing growth rate method is used where the rate of growth shows a downward pattern
iii. The geometrical increase method is used for older cities
Which of the following above statements is/are correct?
a) i, ii, iii
b) i and iii
c) Only ii
d) ii and iii

Answer: c
Explanation: Arithmetical increase method is suitable for older cities, whereas a geometrical increase method is suitable for new cities.

3. Which method is suitable if the growth rate is decreasing and the population is reaching towards saturation?
a) Arithmetical increase method
b) Graphical comparison method
c) Zoning method
d) Decreased rate of growth method

Answer: d
Explanation: In decreased rate of growth method, growth rate is decreasing and the population is reaching towards saturation and is only valid when growth rate shows a downward pattern

4.Which method of population forecast is suitable when extension is required for small duration and past record is available for long duration?
a) Graphical comparison method
b) Graphical extension method
c) Logistic curve method
d) Zoning method

Answer: b
Explanation: In the graphical extension method, a curve is drawn between population and time up to the present period, then the curve is extended from present to the future decade and the population is approximately determined from the extended part of the curve

5. The size of suspended solids lies in the range of ________
a) 10-3 – 10-6 mm
b) 103 – 106 mm
c) 10-1 – 10-3 mm
d) 101 – 103 mm

Answer: c
Explanation: Size of suspended solids – 10-1 – 10-3 mm, size of colloidal solids – 10-3 – 10-6 mm, size of dissolved solids < 10-6 mm

6. Suspended solids are measured by which of the following?
a) Turbidity rod
b) Gravimetric test
c) Chromatography
d) Jackson’s turbidity meter

Answer: b
Explanation: Turbidity rod and Jackson’s turbidity meter is used to find turbidity whereas chromatography is used to detect odour. Hence b is the correct answer

7.The maximum permissible limit for suspended solids is ____________
a) 10 mg/l
b) 20 mg/l
c) 30 mg/l
d) 40 mg/l

Answer: c
Explanation: The maximum permissible limit for suspended solids is 30mg/l for testing waste water which is set by the Environmental Protection Agency (EPA)

8. Identify the correct relation between the following?
a) Dissolved solid = Total solid + Suspended solid
b) Dissolved solid = Total solid – Suspended solid
c) Total solid = Dissolved solid / Suspended solid
d) Dissolved solid = Suspended solid – Total solid

Answer: b
Explanation: Dissolved solid is the difference between total solid and suspended solid. Suspended solid is non-filterable solid whereas dissolved solid is filterable solid

9. Which method is used to measure the color of water?
a) Gravimetric analysis
b) Chromatography
c) Tintometer method
d) Hydrometer analysis

Answer: c
Explanation: The colors in water are measured by Tintometer method. It is measured on Burgess scale or cobalt scale by Nessler’s tube.

10. 1 TCU (True Color Unit) is equivalent to _____
a) The color produced by 1 g of platinum cobalt
b) The color produced by 1 mg of platinum cobalt
c) The color produced by 1 mg of platinum cobalt in 1L of distilled water
d) The color produced by 1 mg of platinum cobalt in 1mL of distilled water

Answer: c
Explanation: 1 TCU (True Color Unit) is equivalent to color produced by 1 mg of platinum cobalt in 1L of distilled water. The true color unit is also called a Hazen unit.