Related Questions

The correct relation between theoretical oxygen demand (TOD), Biochemical oxygen demand (BOD) and Chemical oxygen demand (COD) is given by
A TOD > BOD > COD
B TOD > COD > BOD
C BOD > COD > TOD
D COD > BOD > TOD
When the primary direct crank of a reciprocating engine makes an angle of $$\theta $$ with the line of stroke, then the secondary direct crank will make an angle of _________ with the line of stroke.
A $$\frac{\theta }{2}$$
B $$\theta $$
C $$2\theta $$
D $$4\theta $$
একটি অক্সিজেন সিলিন্ডারের আয়তন 10 x 105 cm3 এবং এতে 300 বায়ুমন্ডলীয় চাপে অক্সিজেন ভর্তি আছে। কিছুটা ব্যবহারের পর দেখা গেল যে, চাপ 200 বায়ুমন্ডলীয় চাপে নেমে গেছে। ব্যবহারকৃত অক্সিজেনের আয়তন কত?(The volume of an oxygen cylinder is 10 x 105 cm3 and pressure is 300 atm. After some use, the pressure drops to 200 atm. What is the volume of the used oxygen?)
A 1000 L
B 500 L
C 2000 L
D 1200 L
E 1500 L
One molecule of oxygen consists of __________ atoms of oxygen.
A 2
B 4
C 8
D 16
The relative stability of a sewage sample, whose dissolved oxygen is same as the total oxygen required to satisfy BOD, is
A 1
B 100
C Infinite
D Zero
Oxygen is separated by distillation from air after its liquefaction. The boiling point of oxygen is about __________ °C.
A -83
B -183
C -196
D -218
The ratio of oxygen available to the oxygen required for stabilisation of sewage is called the
A Bacterial stability factor
B Relative stability
C Biological oxygen demand (BOD)
D Oxygen ion concentration
A company makes a profit of 7% selling goods which cost Tk.2000; it also makes a profit of 6% selling a machine the cost the company Tk. 5000. How much total profit did the company make on both transactions?
A Tk. 300
B Tk. 400
C Tk. 420
D Tk. 440
Rana makes a 40% profit by selling his home, but loses 12% of the profit to taxes. what is the net percentage of profit Rana makes on the sale?
A 2.8%
B 4.8%
C 25.2%
D 35.2%
A bicycle company makes five styles of bikes in seven different colors. How many different bicycles can the company makes when considering both style and color?
A 35
B 12
C 7
D 5

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