OIT EXAM QUESTIONS AND
ANSWERS 100% CORRECT!!
(REVISION PAPER)
,
, What are colloids? - ANSWER Very small particles suspended in water which are
resistant to settling.
What is turbidity measured in? - ANSWER Nephelometric Turbidity Units (NTU)
What is the turbidity measurement that is visible to the naked eye? - ANSWER 5
NTU
What is an important indicator of treatment efficiency and particularly the efficiency of
filters and disinfection processes? - ANSWER Turbidity
Why are particles that cause turbidity harmful? - ANSWER They can hide or entrap
harmful organisms so that the disinfectant is unable to reach them. It calls increases
CL demand which can be carcinogenic
What are the 2 types of sampling? - ANSWER Grab samples and composite
samples
What are grab samples and when is it used? - ANSWER A single sample taken at
one place and time. Used when water quality and quantity are not variable
What is a composite sample and when is it used? - ANSWER A series of samples
taken over a period of time which are combined to form a single sample. Necessary
if water quality changes greatly over time.
What is voltage? - ANSWER Electrical potential or potential difference between two
points. Indicated the strength of the "push" on current
What is current and what are its units? - ANSWER Flow off electric charge.
Measured in amperes
What is the typical rate of change (Hz) or alternating current? - ANSWER 60 cycles
per second
ANSWERS 100% CORRECT!!
(REVISION PAPER)
,
, What are colloids? - ANSWER Very small particles suspended in water which are
resistant to settling.
What is turbidity measured in? - ANSWER Nephelometric Turbidity Units (NTU)
What is the turbidity measurement that is visible to the naked eye? - ANSWER 5
NTU
What is an important indicator of treatment efficiency and particularly the efficiency of
filters and disinfection processes? - ANSWER Turbidity
Why are particles that cause turbidity harmful? - ANSWER They can hide or entrap
harmful organisms so that the disinfectant is unable to reach them. It calls increases
CL demand which can be carcinogenic
What are the 2 types of sampling? - ANSWER Grab samples and composite
samples
What are grab samples and when is it used? - ANSWER A single sample taken at
one place and time. Used when water quality and quantity are not variable
What is a composite sample and when is it used? - ANSWER A series of samples
taken over a period of time which are combined to form a single sample. Necessary
if water quality changes greatly over time.
What is voltage? - ANSWER Electrical potential or potential difference between two
points. Indicated the strength of the "push" on current
What is current and what are its units? - ANSWER Flow off electric charge.
Measured in amperes
What is the typical rate of change (Hz) or alternating current? - ANSWER 60 cycles
per second
