Related Questions

Disinfection of water is done to destroy pathogenic bacteria and thus prevent water-borne diseases. Disinfection of water may be done by the use of
A Ozone and iodine
B Chlorine or its compounds
C Ultraviolet light for irradiation of water
D All of the above
Residual chlorine in water is determined by
A Starch iodide method
B Orthotolidine method
C Both (A) and (B)
D None of the above
Maximum permissible residual chlorine in treated water should be __________ mg/litre.
A 0.001 to 0.01
B 02 to 0.3
C 2 to 3
D 5 to 10
Normal dosage of chlorine in public water supply scheme ranges from __________ ppm.
A 0.5 to 1
B 10 to 15
C 300 to 500
D 1000 to 1500
A company owns some land and buildings for which the following details are relevant : Cost of land Taka 50,000; cost of building Taka 100,000, estimated life of building 20 years, estimated residual value of building Taka 2000; estimated residual value of land Taka 50,000. The company uses the straight line depreciation method. Which is the correct annual depreciation charge for this asset?
A Taka 4000
B Taka 4900
C Taka 7400
D Taka 7500
The number of bacteria in a colony was growing exponentially . At 1 pm yesterday the number of bacteria was 1000 and at 3 pm yesterday it was 4000. How many bacteria were there in the colony at 6 pm yesterday ?
A 32,000
B 80,000
C 60,072
D 7,683
A certain population of bacteria doubles every 10 minutes. If the number of bacteria in the population initially was 104, what was the number of bacteria in the population 1 hour later?
A 2(104)
B 6(104)
C (26) (104)
D (106)(104)
It takes 30 days to fill a laboratory dish with bacteria, If the size of the bacteria doubles each days, how long will it take for the bacteria to fill one-----half of the dish?
A 10 days
B 15 days
C 24 days
D 29 days
Pathogens (or pathogenic bacterias) in water may cause
A Typhoid
B Cholera
C Dysentery
D All the above
h,J,K,L,M,N and O are the only legislators eligible to vote on Bills 1,2 and 3, each of which will be passed if at least four legislators eligible vote in favor of it. each legislator must vote on all three bills; on abstentions are possible. The following is known : *H must vote against all three bills; each of the other legislators must vote in favor of at least one bill and against at lest one bill. *j must vote against Bills 1. *O Must vote against Bills 2 and 3. * L must the same way that K dose on all three bills.*N must vote the same way that O dose on all three bills. which of the following must vote in favor of Bill 1 ?
A J
B K
C L
D O

Next steps