Combustion MCQs : This section focuses on the "Combustion". These Multiple Choice Questions (MCQs) should be practiced to improve the Combustion skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.
Question 1
____________ is a chemical reaction in which certain elements of the fuel like hydrogen and carbon combine with oxygen liberating heat energy and causing an increase in temperature of the gases.
A. Compression
B. Expansion
C. Combustion
D. None of the mentioned
Question 2
A pre-combustion chamber gives a shorter delay compared to an open type of combustion chamber.
A. TRUE
B. FALSE
Question 3
Homogeneous mixture is formed inside the engine cylinder and the combustion is initiated inside the cylinder at a particular instant towards the end of the compression stroke.
A. TRUE
B. FALSE
Question 4
In spark ignition engines a nearly ____________ mixture of air and fuel is formed in the carburettor.
A. heterogeneous
B. homogeneous
C. solid
D. none of the mentioned
Question 5
The ____________ rate is due to the physical movement of the flame front relative to the cylinder wall and also the result of the pressure differential between the burning gases and the unburnt gases in the combustion chamber.
A. transposition
B. reaction
C. burning
D. none of the mentioned
Question 6
The ____________ rate is the result of a purely chemical combination process in which the flame eats it way into the unburned charge.
A. transposition
B. reaction
C. burning
D. none of the mentioned
Question 7
The complete combustion of ____________ mixture, and droplet combustion result in the smoke and odour.
A. heterogeneous
B. homogeneous
C. solid
D. none of the mentioned
Question 8
The conditions necessary for combustion are the presence of combustible mixture and some means of initiating the process.
A. TRUE
B. FALSE
Question 9
The process of combustion in engines generally takes place either in a homogeneous or a heterogeneous fuel vapour air mixture depending on the type of engine.
A. TRUE
B. FALSE
Question 10
10 moles of ethane is supplied with 49 moles of oxygen, what is the percentage of excess oxygen?
A. 20%
B. 40%
C. 50%
D. 70%
Question 11
144 grams of C5H12 is burnt with 64 grams O2, and 44 grams of CO2 is formed, what is the percentage of excess O2?
A. 25%
B. 50%
C. 75%
D. 100%
Question 12
Ethene is burnt with 150% of excess air, what is the percentage of O2 in the products?
A. 12.5%
B. 33.3%
C. 45.4%
D. 52.9%
Question 13
Ethene is burnt with 50% of excess air, what is the percentage of CO2 in the products?
A. 11.11%
B. 36.36%
C. 66.66%
D. 72.72%
Question 14
Methane is at the rate 50 moles is supplied to a reactor with air at the rate 1000 moles, the reactor leaves O2, N2, CO2 and H2O, what is the percentage of CO2 in products?
A. 4.7%
B. 10.4%
C. 16.5%
D. 24.3%
Question 15
Methane is at the rate 50 moles is supplied to a reactor with air at the rate 1000 moles, the reactor leaves O2, N2, CO2 and H2O, what is the percentage of H2O in products?
A. 5.8%
B. 9.5%
C. 15.4%
D. 20.7%
Question 16
Methane is at the rate 50 moles is supplied to a reactor with air at the rate 1000 moles, the reactor leaves O2, N2, CO2 and H2O, what is the percentage of N2 in products?
A. 25.4%
B. 45.2%
C. 75.2%
D. 95.6%
Question 17
Methane is at the rate 50 moles is supplied to a reactor with air at the rate 1000 moles, the reactor leaves O2, N2, CO2 and H2O, what is the percentage of O2 in products?
A. 10.4%
B. 25.8%
C. 45.6%
D. 78.2%
Question 18
Methane is at the rate 50 moles is supplied to a reactor with air at the rate 1000 moles, the reactor leaves O2, N2, CO2 and H2O, what is the rate of products?
A. 900 moles
B. 950 moles
C. 1000 moles
D. 1050 moles
Question 19
Octane is burnt with 40% excess O2, what is the percentage of CO2 in products?
A. 18.18%
B. 36.36%
C. 54.54%
D. 72.72%
Question 20
Pentane is burnt with 100% of excess air, what is the percentage of H2O in the products?
A. 12.4%
B. 34.6%
C. 42.1%
D. 56.9%
Question 21
Propane is burnt with 20% excess O2, what is the percentage of CO2 in products?
A. 12.5%
B. 25%
C. 45%
D. 75.5%
Question 22
What is the percentage of excess air if 50 grams of air is in excess and 150 grams of air enters the process?
A. 10%
B. 25%
C. 50%
D. 100%
Question 23
What is the percentage of excess air, if 10 moles of air entered the process and only 5 moles of that are required?
A. 10%
B. 50%
C. 75%
D. 100%