Environmental Engineering Multiple Choice Questions on “Physical characteristic of Water”.
1. 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
Clarification: 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.
2. Suspended solids are measured by which of the following?
a) Turbidity rod
b) Gravimetric test
c) Chromatography
d) Jackson’s turbidity meter
Answer: b
Clarification: 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.
3. 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
Clarification: The maximum permissible limit for suspended solids is 30mg/l for testing waste water which is set by the Environmental Protection Agency (EPA).
4. 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
Clarification: Dissolved solid is the difference between total solid and suspended solid. Suspended solid is non-filterable solid whereas dissolved solid is filterable solid.
5. Which method is used to measure the color of water?
a) Gravimetric analysis
b) Chromatography
c) Tintometer method
d) Hydrometer analysis
Answer: c
Clarification: The colors in water are measured by Tintometer method. It is measured on Burgess scale or cobalt scale by Nessler’s tube.
6. 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
Clarification: 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.
7. The range for threshold odour number is __________
a) 0-3
b) 1-5
c) 1-3
d) 0-5
Answer: c
Clarification: The maximum value of Threshold odour number is 3 and its range is 1-3. The threshold odour number is used to measure the intensity of taste and odour.
8. Threshold odour number testing is preferred in hot water.
a) True
b) False
Answer: b
Clarification: TON testing is preferred in cold water as in hot water due to increase in temperature, taste and odour can change.
9. One JTU is equivalent to turbidity produced by __________
a) 1mg of fine silica dissolved in 1L of distilled water
b) 1g of fine silica dissolved in 1L of distilled water
c) 1g of fine silica dissolved in 1ml of distilled water
d) 1mg of fine silica dissolved in 1ml of distilled water