Multiple choice question for engineering
Set 1
1. Material balance equation can be applied to
a) Total mass
b) Mass of a component
c) Moles of a component
d) All of the mentioned
Answer
Answer: d [Reason:] Material balance equation can be applied to all these as these are conserved under every change in a chemical process.
2. Material balance equation cannot be applied to
a) Total moles
b) Mass of an atomic species
c) Moles of an atomic species
d) All of the mentioned
Answer
Answer: a [Reason:] Total moles may vary.
3. We don`t use volume balance in a chemical process because
a) Mass is not conserved in a process
b) Volume is not conserved in a process
c) Both a and b
d) Neither a nor b
Answer
Answer: b [Reason:] Volume is not conserved in a process because different materials have different densities.
4. In the given tank, there are two feeds and one output. Consider a 2 hour operation; the feed rates are 4000 kg/hr and 6000 kg/hr. The accumulated material inside the tank is 2000 kg. What is the output rate kg/hr of the material?
a) 9000
b) 8000
c) 7000
d) 6000
Answer
Answer: a [Reason:] Input = output, Take a basis: 2 hour.
5. In a process the inputs and outputs are shown as in the diagram
Correct material balance is
a) B+C = A+D
b) A+B = C+D
c) A+C = B+D
d) None of the mentioned
Answer
Answer: a [Reason:] What comes in, goes out.
6. Based on number of degrees of freedom, find the incorrect statement, consider
NU = Number of unknown
NE = Number of unknown equation
a) NU = NE for that a solution
b) NU > NE > 0 for that more independent equation required
c) NU< NE < 0 for that no solution exists unless some constraints are eliminated
d) None of the mentioned
Answer
Answer: d [Reason:] ND = NU – NE
Where: ND = Number of degrees of freedom.
7. In a process, two feed streams are there and one output stream. The feed streams have the feed rates as 500 kg/sec and 600 kg/sec. If the output stream rate is 800 kg/s, what is the mass stored in the chamber in five seconds?
a) 300 kg
b) 500 kg
c) 1000 kg
d) 1500 kg
Answer
Answer: d [Reason:] For five seconds, Accumulation = 5(500+600-800) Kg.
8 – 10. For the given steady state system, consider that a unique solution exists for the process.
ω1, ω2, ω3 are the mass fractions of the components 1, 2 and 3.
8. What is the value of ω2 for A?
a) 0.5
b) 0.6
c) 0.7
d) 0.8
Answer
Answer: a [Reason:] Σω = 1.
9. What ids the value of ω2 for P?
a) 0.98
b) 0.88
c) 0.78
d) 0.68
Answer
Answer: d [Reason:] ω2F + ω2A = ω2P.
10. What ids the value of ω3 for P?
a) 0.09
b) 0.08
c) 0.07
d) 0.06
Answer
Answer: b [Reason:] ω3A = ω3P.
Set 2
1. Any arbitrary portion of or whole process that is considered for analysis is called
a) System
b) Boundary
c) Surrounding
d) None of the mentioned
Answer
Answer: a [Reason:] Any arbitrary portion of or whole process that is considered for analysis is called system.
2. _________ is the line that encloses the portion of the process that you want to analyse.
a) System
b) Surrounding
c) System Boundary
d) None of the mentioned
Answer
Answer: c [Reason:] System Boundary is the line that encloses the portion of the process that you want to analyse.
3. A system that does not have material crossing the system boundary is called
a) Closed System
b) Open System
c) Steady state system
d) None of the mentioned
Answer
Answer: a [Reason:] A system that does not have material crossing the system boundary is called Closed System.
4. In open system the material crosses the boundary.
The above given statement is
a) Incorrect
b) Correct
c) Correct for closed system
d) None of the mentioned
Answer
Answer: a [Reason:] In open system the material crosses the boundary.
5. Open system is also called a _______ system.
a) Flow
b) Free
c) Steady
d) None of the mentioned
Answer
Answer: a [Reason:] Open system is also called a flow system.
6. A system in which all conditions remain constant with time is called
a) Open system
b) Closed system
c) Steady state system
d) None of the mentioned
Answer
Answer: c [Reason:] A system in which all conditions remain constant with time is called Steady state system.
7. An increase or decrease in the material in a system is called _________
a) Accumulation
b) Negative accumulation
c) Positive accumulation
d) None of the mentioned
Answer
Answer: a [Reason:] An increase or decrease in the material in a system is called accumulation.
8. A depletion of material in a system is called ______________
a) Accumulation
b) Negative accumulation
c) Positive accumulation
d) None of the mentioned
Answer
Answer: b [Reason:] A depletion of material in a system is called Negative accumulation.
9. Pseudo steady state is not truly steady state but for convenience is treated as steady state.
The above statement for a process is
a) Correct
b) Incorrect
c) Never incorrect
d) None of the mentioned
Answer
Answer: a [Reason:] Pseudo steady state is not truly steady state but for convenience is treated as steady state.
10. Quasi-steady state is same as
a) Pseudo steady state
b) Open system
c) Close system
d) None of the mentioned
Answer
Answer: a [Reason:] Pseudo steady state is same as quasi steady state.
Set 3
1. Any arbitrary portion of or whole process that is considered for analysis is called
a) System
b) Boundary
c) Surrounding
d) None of the mentioned
Answer
Answer: a [Reason:] Any arbitrary portion of or whole process that is considered for analysis is called system.
2. _________ is the line that encloses the portion of the process that you want to analyse.
a) System
b) Surrounding
c) System Boundary
d) None of the mentioned
Answer
Answer: c [Reason:] System Boundary is the line that encloses the portion of the process that you want to analyse.
3. A system that does not have material crossing the system boundary is called
a) Closed System
b) Open System
c) Steady state system
d) None of the mentioned
Answer
Answer: a [Reason:] A system that does not have material crossing the system boundary is called Closed System.
4. In open system the material crosses the boundary.
The above given statement is
a) Incorrect
b) Correct
c) Correct for closed system
d) None of the mentioned
Answer
Answer: a [Reason:] In open system the material crosses the boundary.
5. Open system is also called a _______ system.
a) Flow
b) Free
c) Steady
d) None of the mentioned
Answer
Answer: a [Reason:] Open system is also called a flow system.
6. A system in which all conditions remain constant with time is called
a) Open system
b) Closed system
c) Steady state system
d) None of the mentioned
Answer
Answer: c [Reason:] A system in which all conditions remain constant with time is called Steady state system.
7. An increase or decrease in the material in a system is called _________
a) Accumulation
b) Negative accumulation
c) Positive accumulation
d) None of the mentioned
Answer
Answer: a [Reason:] An increase or decrease in the material in a system is called accumulation.
8. A depletion of material in a system is called ______________
a) Accumulation
b) Negative accumulation
c) Positive accumulation
d) None of the mentioned
Answer
Answer: b [Reason:] A depletion of material in a system is called Negative accumulation.
9. Pseudo steady state is not truly steady state but for convenience is treated as steady state.
The above statement for a process is
a) Correct
b) Incorrect
c) Never incorrect
d) None of the mentioned
Answer
Answer: a [Reason:] Pseudo steady state is not truly steady state but for convenience is treated as steady state.
10. Quasi-steady state is same as
a) Pseudo steady state
b) Open system
c) Close system
d) None of the mentioned
Answer
Answer: a [Reason:] Pseudo steady state is same as quasi steady state.
Set 4
1. A system in which one or more than one conditions vary with time is called
a) Open system
b) Closed system
c) Steady state system
d) Unsteady state system
Answer
Answer: d [Reason:] A system in which one or more than one conditions vary with time is called Unsteady state system.
2. Unsteady state system is also known as
a) Open system
b) Closed system
c) Transient system
d) None of the mentioned
Answer
Answer: c [Reason:] Unsteady state system is also known as transient system.
3. A ____________ is one in which material enters and leaves the system without interruption.
a) Continuous process
b) Batch process
c) Semi-batch process
d) None of the mentioned
Answer
Answer: a [Reason:] A continuous is one in which material enters and leaves the system without interruption.
4. ______________is a process in which material is neither added nor removed from a process during operation.
a) Continuous process
b) Batch process
c) Semi-batch process
d) None of the mentioned
Answer
Answer: b [Reason:] Batch process is a process in which material is neither added nor removed from a process during operation.
5. Soup preparation is an example of _______where nothing is added in between the process.
a) Continuous process
b) Batch process
c) Semi-batch process
d) None of the mentioned
Answer
Answer: b [Reason:] Batch process treats a fixed amount of material.
6. A process in which material enters the system but product is not removed during operation is called
a) Continuous process
b) Batch process
c) Semi-batch process
d) None of the mentioned
Answer
Answer: c [Reason:] A process in which material enters the system but product is not removed during operation is called semi-batch process.
7. The depletion of a component in a system due to chemical reaction is _________
a) Consumption
b) Degradation
c) Decomposition
d) None of the mentioned
Answer
Answer: a [Reason:] The depletion of a component in a system due to chemical reaction is consumption.
8. Find out the incorrect statement
a) Accumulation for a process can be negative
b) Accumulation for a process can be positive
c) Accumulation for a process can be zero
d) None of the mentioned
Answer
Answer: d [Reason:] Accumulation for a process can be negative, positive and zero.
9. A volatile solid material is placed in a tube and vacuum is created inside the tube. If the tube is heated and the solid vaporizes the weight of the material + tube will
a) Decrease
b) Increase
c) Remains same
d) None of the mentioned
Answer
Answer: c [Reason:] Apply mass conservation.
10. The following statement is
If the overall flows in and out for over a time period for several batches are considered, and local batches ignore, the process can be treated as continuous.
a) False
b) True
c) Depends on the process
d) None of the mentioned
Answer
Answer: b [Reason:] Over a time period for several batches, a process behaves like a continuous process if local batches are neglected.
Set 5
1. A system in which one or more than one conditions vary with time is called
a) Open system
b) Closed system
c) Steady state system
d) Unsteady state system
Answer
Answer: d [Reason:] A system in which one or more than one conditions vary with time is called Unsteady state system.
2. Unsteady state system is also known as
a) Open system
b) Closed system
c) Transient system
d) None of the mentioned
Answer
Answer: c [Reason:] Unsteady state system is also known as transient system.
3. A ____________ is one in which material enters and leaves the system without interruption.
a) Continuous process
b) Batch process
c) Semi-batch process
d) None of the mentioned
Answer
Answer: a [Reason:] A continuous is one in which material enters and leaves the system without interruption.
4. ______________is a process in which material is neither added nor removed from a process during operation.
a) Continuous process
b) Batch process
c) Semi-batch process
d) None of the mentioned
Answer
Answer: b [Reason:] Batch process is a process in which material is neither added nor removed from a process during operation.
5. Soup preparation is an example of _______where nothing is added in between the process.
a) Continuous process
b) Batch process
c) Semi-batch process
d) None of the mentioned
Answer
Answer: b [Reason:] Batch process treats a fixed amount of material.
6. A process in which material enters the system but product is not removed during operation is called
a) Continuous process
b) Batch process
c) Semi-batch process
d) None of the mentioned
Answer
Answer: c [Reason:] A process in which material enters the system but product is not removed during operation is called semi-batch process.
7. The depletion of a component in a system due to chemical reaction is _________
a) Consumption
b) Degradation
c) Decomposition
d) None of the mentioned
Answer
Answer: a [Reason:] The depletion of a component in a system due to chemical reaction is consumption.
8. Find out the incorrect statement
a) Accumulation for a process can be negative
b) Accumulation for a process can be positive
c) Accumulation for a process can be zero
d) None of the mentioned
Answer
Answer: d [Reason:] Accumulation for a process can be negative, positive and zero.
9. A volatile solid material is placed in a tube and vacuum is created inside the tube. If the tube is heated and the solid vaporizes the weight of the material + tube will
a) Decrease
b) Increase
c) Remains same
d) None of the mentioned
Answer
Answer: c [Reason:] Apply mass conservation.
10. The following statement is
If the overall flows in and out for over a time period for several batches are considered, and local batches ignore, the process can be treated as continuous.
a) False
b) True
c) Depends on the process
d) None of the mentioned
Answer
Answer: b [Reason:] Over a time period for several batches, a process behaves like a continuous process if local batches are neglected.