Multiple choice question for engineering
Set 1
1. If the aperture size of the filtration medium is too small, it causes high pressure drops.
a) True
b) False
Answer
Answer: a [Reason:] If the aperture size of the filtration medium is too small, it causes high pressure drops.
2. Statement 1: Filter cake increases the efficiency of filtration.
Statement 2: Filter aid is added to the filter cake when the filter cake is the desired product.
a) True, False
b) True, True
c) False, False
d) False, True
Answer
Answer: a [Reason:] Filter cake increases the efficiency of filtration as it offers some amount of resistance. Filter aid is added to the filtrate when the filter cake is the desired product.
3. What is the effect of pressure drop on the filtration rate?
a) Increases
b) Deceases
c) Varies depending on the compressibility
d) None of the mentioned
Answer
Answer: c [Reason:] Effect of pressure drop on the filtration rate varies depending on the compressibility.
4. Which of the following is the cheapest filtration equipment?
a) Plate and frame filter press
b) Pressure leaf filter press
c) Continuous Rotary Vacuum Filter Press
d) None of the mentioned
Answer
Answer: a [Reason:] Plate and frame filter press is the cheapest filtration equipment among all the equipment.
5. Which of the following filtration equipment offers maximum pressure drop?
a) Plate and frame filter press
b) Pressure leaf filter press
c) Continuous Rotary Vacuum Filter Press
d) None of the mentioned
Answer
Answer: b [Reason:] Pressure leaf filter press offers maximum pressure drop.
6. Which of the following filtration equipment operates under continuous operation?
a) Plate and frame filter press
b) Pressure leaf filter press
c) Continuous Rotary Vacuum Filter Press
d) None of the mentioned
Answer
Answer: c [Reason:] Continuous Rotary Vacuum Filter Press operates under continuous operation.
7. Which of the following factors is a genuine criterion for the selection of a filter press?
a) Equipment life
b) Availability of floor area
c) Chemical reactivity
d) All of the mentioned
Answer
Answer: d [Reason:] All of the mentioned factors are a genuine criterion for the selection of a filter press.
8. Which of the following factor does the rate of filtration depend on?
a) Compressibility factor of the filtrate
b) Pressure drop
c) Both of the mentioned
d) Neither of the mentioned
Answer
Answer: c [Reason:] Rate of filtration depends on both of the mentioned factors.
9. Cellulose was added in the pulping of certain fruit juices. What is it called? Was the decision of it being added in this process of filtration correct?
a) Filter cloth, yes
b) Filter aid, yes
c) Filter cloth, no
d) Filter aid, no
Answer
Answer: b [Reason:] Cellulose was added in the pulping of certain fruit juices as a filter aid. Since in this case, the filtrate is the desired product, the decision is right as the cellulose stays inside the filter cake after the process is over and doesn’t affect the filtrate.
10. Statement 1: Continuous Rotary vacuum filter press has a high labor cost.
Statement 2: Continuous Rotary vacuum filter press has a high clogging.
a) True, False
b) True, True
c) False, False
d) False, True
Answer
Answer: c [Reason:] Plate and frame filter press have both, a high labor cost and high clogging in their cloths.
Set 2
1. 
‘a’ refers to ______ and ‘b’ refers to _____
a) Steady state heat transfer, Unsteady state heat transfer
b) Unsteady state heat transfer, Steady state heat transfer
c) None of the mentioned
d) All of the mentioned
Answer
Answer: a [Reason:] ‘a’ refers to Steady state heat transfer and ‘b’ refers to unsteady state heat transfer.
2. The equation
Answer
Answer: b [Reason:] The equation dq/dA= (k(-dT))/dx is called Fourier’s law conduction.
3. Statement 1: The heat transfer co-efficient in ice is four times that of water.
Statement 2: k in conductance is for thermal conductivity.
a) True, False
b) True, True
c) False, False
d) False, True
Answer
Answer: b [Reason:] Both the statements are true.
4. Frozen foods have a higher transfer co-efficient hence they lose heat faster than other food items when exposed to outside environment.
a) True
b) False
Answer: a
Answer
Explanation: Frozen foods have a higher transfer co-efficient hence they lose heat faster than other food items when exposed to outside environment.
5. Statement 1: When average radius gives an error, log mean radius is used.
Statement 2: Log mean radius is given by rL= ( r0– ri )/(ln(r0/ri))
a) True, False
b) True, True
c) False, False
d) False, True
Answer
Answer: b [Reason:] Both the statements are true.
6. Statement 1: α=k/(ρCp)
Statement 2: α stands for thermal conductivity.
a) True, False
b) True, True
c) False, False
d) False, True
Answer
Answer: a [Reason:] α=k/(ρCp) . α stands for thermal diffusivity.
7. Statement 1: NFo stands for Fourier number.
Statement 2: NFo= (αtT)/s2
a) True, False
b) True, True
c) False, False
d) False, True
Answer
Answer: b [Reason:] Both the statements pertaining to Fourier number are true.
8. NFo= (αtT)/s2 . Here ‘s’ stands for half slab thickness. Based on this data, ‘s’ for a chapatti/ dosa will be _____
a) Half slab thickness
b) Full slab thickness
c) One and a half slab thickness
d) Double slab thickness
Answer
Answer: b [Reason:] ‘s’ for a chapatti/ dosa will be Full slab thickness. This is because ‘s’ equals half slab thickness only when heating takes place from both sides. But, for a chapatti/ dosa, heating takes place only from one end hence‘s’ becomes ‘2s’.
9. _____ is the equation for unsteady state heat conduction through solid materials.
a) dT/dx= α (d2 T)/ (dt)2
b) dT/dx= α (d2 T)/ (dx)2
c) dT/dt= α (d2 T)/ (dx)2
d) dT/dt= α (d2 T)/ (dt)2
Answer
Answer: c [Reason:] dT/dt= α (d2 T)/ (dx)2 is the equation for unsteady state heat conduction through solid materials.
10. For a copper pipe, k = 0.3534, temperature difference = 60, B = 0.0125 and A = 850. What is the value of q?
a) 1442 W
b) 1442 kW
c) 1565 W
d) 1565 kW
Answer
Answer: b [Reason:] q=kA ∆T/B
Set 3
1. Which of the following application is a belt conveyor used for?
a) Material transportation over long distances
b) Material transportation within premises
c) Material transportation for processing
d) All of the mentioned
Answer
Answer: d [Reason:] Belt conveyors are used for all of the mentioned uses.
2. Statement 1: It is generally not possible to change the direction of flow with belt conveyors.
Statement 2: If belt conveyors are to be used in the bent position, slat belts are used.
a) True, False
b) True, True
c) False, False
d) False, True
Answer
Answer: b [Reason:] It is generally not possible to change the direction of flow with belt conveyors. If belt conveyors are to be used in the bent position, slat belts are used.
3. Slat belts are made up of_____
a) Wood
b) Plastic
c) Metal
d) Any of the mentioned
Answer
Answer: d [Reason:] Slat belts can be made up of any of the mentioned.
4. Statement 1: Belt conveyors cannot be used in the inclined position.
Statement 2: Screw conveyors can carry more amount of load compared to belt conveyors.
a) True, False
b) True, True
c) False, False
d) False, True
Answer
Answer: c [Reason:] Belt conveyors can be used in the inclined position. Belt conveyors can carry more amount of load compared to screw conveyors. As high as 5000 tons per hour as compared to screw conveyors which carry 4.7 m3/minute.
5. In the specifications of a screw conveyor, the shaft length is shorter than the flight length.
a) True
b) False
Answer
Answer: b [Reason:] In the specifications of a screw conveyor, the shaft length is more than the flight length. The shaft length covers the length of the entire shaft whereas the flight length only covers the length of the first screw (starting from one end) to the last screw.
6. Statement 1: Chain drive rollers move faster than belt driven rollers.
Statement 2: Screw conveyors are used in the feeding of raw materials like wheat or chilly into the grinding unit to make powder out of it.
a) True, False
b) True, True
c) False, False
d) False, True
Answer
Answer: b [Reason:] Chain drive rollers move faster than belt driven rollers. Screw conveyors are used in the feeding of raw materials like wheat or chilly into the grinding unit to make powder out of it.
7. Pneumatic conveying is done under which of the mentioned conditions?
a) High pressure
b) Vacuum
c) Fluidization
d) Any of the mentioned
Answer
Answer: d [Reason:] Pneumatic conveying can be done under any of the mentioned conditions.
8. What is the flow rate of materials in a bucket conveyor dependent on?
a) Shape of the buckets
b) Spacing of the buckets
c) Speed of the conveyor
d) All of the mentioned
Answer
Answer: d [Reason:] All of the mentioned parameters affect the flow rate of materials in a bucket conveyor.
9. Statement 1: Bucket conveyors can be divided into close and spaced bucket conveyors.
Statement 2: Bucket conveyors can be divided into centrifugal and positive discharge bucket conveyors.
a) True, False
b) True, True
c) False, False
d) False, True
Answer
Answer: b [Reason:] Bucket conveyors can be divided both the ways based on different parameters.
10. Which of the following is NOT an advantage of mechanical transportation?
a) Transportation is economical and quick
b) Handling is contamination free
c) No human injury
d) None of the mentioned
Answer
Answer: d [Reason:] Given are all advantages of mechanical transportation.
11. Fork-lift trolleys are a combination of chain hoists and interlock transfer cranes.
a) True
b) False
Answer
Answer: b [Reason:] Interlock transfer cranes are a combination of chain hoists and fork-lift trolleys.
12. In food industry, the animal processing sector requires mechanical transportation to minimize human intervention and to maintain hygiene.
a) True
b) False
Answer
Answer: a [Reason:] In food industry, the animal processing sector requires mechanical transportation to minimize human intervention and to maintain hygiene.
13. Statement 1: Belt and screw conveyors are in all processing units to transport the final packed cartons.
Statement 2: The feeding in most processing units is done by screw feeders or mechanical/oscillatory feeders.
a) True, False
b) True, True
c) False, False
d) False, True
Answer
Answer: b [Reason:] Belt and screw conveyors are in all processing units to transport the final packed cartons. The feeding in most processing units is done by screw feeders or mechanical/oscillatory feeders.
14. Which of the following does NOT include the application of material handling and transportation in food processing?
a) Fruits and vegetables processing
b) Cereals and pulses processing
c) Spices and condiments processing
d) All of the mentioned
Answer
Answer: d [Reason:] All of the mentioned include the application of material handling and transportation in food processing.
15. Statement 1: Cranes and hoists have an incline up and down option.
Statement 2: Trucks can be used for continuous operations.
a) True, False
b) True, True
c) False, False
d) False, True
Answer
Answer: c [Reason:] Cranes and hoists do not have an incline up and down option. Trucks can only be used for intermittent operations.
Set 4
1. Which of the following is a synonym for loss factor of food?
a) Loss tangent
b) Dielectric loss
c) Both of the mentioned
d) None of the mentioned
Answer
Answer: c [Reason:] Loss factor of food is called loss tangent and dielectric loss.
2. Which of the following is true about loss factor of food?
a) It is desirable quality of food
b) It is the ability of food to absorb waves
c) It is represented by Ɛ
d) All of the mentioned
Answer
Answer: d [Reason:] All the given factors are true about loss factor.
3. Penetration depth of food refers to the depth inside the food inside which the heat generation drops to 37%.
a) True
b) False
Answer
Answer: a [Reason:] Penetration depth of food refers to the depth inside the food inside which the heat generation drops to 37%.
4. Which of the following is untrue?
a) It is difficult to predict the electric field intensity inside a food material
b) Design of oven plays an important role in determining the electric filed intensity in a food material
c) Orientations of microwaves is an important role
d) None of the mentioned
Answer
Answer: d [Reason:] It is difficult to predict the electric field intensity inside a food material. Design of oven plays an important role in determining the electric filed intensity in a food material. Orientations of microwaves is an important role.
5. Any food item should be subjected to micro frequencies such that, the dielectric constant is _____ and loss factor is _____
a) Maximum, minimum
b) Maximum, maximum
c) Minimum, minimum
d) Minimum, maximum
Answer
Answer: c [Reason:] Any food item should be subjected to micro frequencies such that, the dielectric constant is minimum and loss factor is minimum.
6. Hannah heats refrigerated rice which has been devoid of moisture and become dry. She heats it in a microwave. It gets unevenly heated. What should she do?
a) Water should be added for even heating
b) She should heat it using equipment that offers conduction or convection
c) None of the mentioned
d) Both of the mentioned
Answer
Answer: a [Reason:] Water has a low dielectric constant due to the generation of friction due to rotation of dipoles. Hence, water should be added for even heating.
7. Statement 1: In microwave heating, heat is not applied to the food item.
Statement 2: Radiation doesn’t gives even drying whereas microwave heating does.
a) True, False
b) True, True
c) False, False
d) False, True
Answer
Answer: b [Reason:] In microwave heating, heat is not applied to the food item. Instead, heat is made to generate within the food item. Radiation doesn’t gives even drying whereas microwave heating does by addition of water. Water has a low dielectric constant due to the generation of friction due to rotation of dipoles. Hence, water should be added for even heating.
8. Statement 1: The factor F0 shows the microbial safety in the food item at the coldest point.
Statement 2: F0 takes the time-temperature data at that particular point and compares conventional heating to microwave heating.
a) True, False
b) True, True
c) False, False
d) False, True
Answer
Answer: b [Reason:] The factor F0 shows the microbial safety in the food item at the coldest point. F0 takes the time-temperature data at that particular point and compares conventional heating to microwave heating.
9. 
Y axis is the density function for volume fraction. X axis is F0
Curve a represents the microwave heating curve and curve b represents the conventional heating pattern. Which of the following statements are true for the above graph?
a) Microwave heating shows a smaller spread hence more uniform heating
b) Heat transfer in microwave heating is faster than in conventional heating
c) Heat transfer in microwave heating is safer than in conventional heating
d) All of the mentioned
Answer
Answer: d [Reason:] All the given statements with respect to the graph are true.
10. One disadvantage of microwave cooking is that the energy efficiency in this process is less.
a) True
b) False
Answer
Answer: b [Reason:] Microwave cooking has very high energy efficiency.
11. Statement 1: Microwave heating helps save electricity.
Statement 2: The quality of product in microwave heating is good hence rejections are lesser.
a) True, False
b) True, True
c) False, False
d) False, True
Answer
Answer: b [Reason:] Microwave cooking has very high energy efficiency. Hence, it helps save electricity. The quality of product in microwave heating is good hence rejections are lesser.
12. Although microwave heating can be used for drying of food containing uneven water content, it is isn’t done for certain food products like garlic. Why?
a) No pasteurization
b) Essential oils being stripped off
c) None of the mentioned
d) Both of the mentioned
Answer
Answer: d [Reason:] For drying of garlic, the essential oils which are the volatile components of the garlic are stripped off from it.
13. Microwave heating is good for puffed products. Why?
a) The rate of heat transfer is more than the rate of moisture loss
b) The heat transfer in these food items takes place so fast that instead of shrinking of the food items due to loss of moisture content, they stay intact and hence puffed
c) None of the mentioned
d) Both of the mentioned
Answer
Answer: d [Reason:] Both of the mentioned statements about microwave heating are correct.
14. Which of the following is NOT a part of the microwave heating system?
a) Magnetron
b) Anode
c) Cathode
d) None of the mentioned
Answer
Answer: d [Reason:] All the given above are parts of a microwave heating system.
15. Recently, cancer causing effects, nutritional destructions of food and biological effects of exposure of microwave heating has come into light.
a) True
b) False
Answer
Answer: a [Reason:] Recently, cancer causing effects, nutritional destruction of food and biological effects of exposure of microwave heating has come into light.
Set 5
1. Which of the following with respect to mixing is true?
a) It is used to distribute heat uniformly to all the components of the mixture
b) Mixing becomes difficult when one of the phases to be mixed is in minor quantity
c) Solid-solid mixing is more difficult than other phases
d) All of the mentioned
Answer
Answer: d [Reason:] All of the mentioned sentences are true with respect to mixing.
2. Statement 1: Root mean square is denoted by σ2
Statement 2: σ2 will show the variation of composition obtained after mixing. Hence the lesser it is, more efficient is the mixing.
a) True, False
b) True, True
c) False, False
d) False, True
Answer
Answer: b [Reason:] Root mean square is denoted by σ2. σ2 will show the variation of composition obtained after mixing. Hence the lesser it is, more efficient is the mixing.
3. Mixing index is applicable for mixing of solids at zero time.
a) True
b) False
Answer
Answer: a [Reason:] Mixing index is applicable for mixing of solids at zero time.
4. Which of the following conditions show that a certain industrial mixer is the best?
a) Power load for mixing is minimum
b) Standard deviation is minimum
c) Time required for mixing is minimum
d) All of the mentioned
Answer
Answer: d [Reason:] All of the mentioned conditions show that a certain industrial mixer is the best.
5. Mixing Index is ratio of the standard deviation of various products during mixing to that at zero mixing.
a) True
b) False
Answer
Answer: a [Reason:] Mixing Index is ratio of the standard deviation of various products during mixing to that at zero mixing.
6. Rate of mixing at any time is give by the extent of mixing at that particular time.
a) True
b) False
Answer
Answer: a [Reason:] Rate of mixing at any time is give by the extent of mixing at that particular time.
7. The force used for mixing by mixing equipment for pastes and dough is _____
a) Centrifugal smearing
b) Impact
c) Tumbling
d) All of the mentioned
Answer
Answer: d [Reason:] The force used for mixing by mixing equipment for pastes and dough can be any of the mentioned.
8. The clearance between the impeller and the vessel in a mixer is usually kept _____
a) High
b) Low
c) Cannot be determined
d) None of the mentioned
Answer
Answer: b [Reason:] The clearance between the impeller and the vessel is usually kept low to avoid stagnant zones.
9. Statement 1: Kneaders are specially used for pastry/viscous liquids in the food industry.
Statement 2: Kneaders are used for mixing dough with fats and making them homogeneous mixtures.
a) True, False
b) True, True
c) False, False
d) False, True
Answer
Answer: b [Reason:] Kneaders are specially used for pastry/viscous liquids in the food industry. Kneaders are used for mixing dough with fats and making them homogeneous mixtures.
10. Statement 1: Effectiveness of mixing in kneaders depends on the blade design.
Statement 2: Kneaders have a high clearance between the two oppositely rotating blades and the vessel.
a) True, False
b) True, True
c) False, False
d) False, True
Answer
Answer: b [Reason:] Effectiveness of mixing in kneaders depends on the blade design. Kneaders have a high clearance between the two oppositely rotating blades and the vessel, unlike other mixers which have a low clearance.
11. Statement 1: Which mixture is used when one of the components is very less in quantity?
Statement 2: This mixer is used to mix items in savory or a snack item.
a) Ribbon mixer, planetary mixer
b) Planetary mixer, double cone mixer
c) Double cone mixer, double cone mixer
d) Planetary mixer, planetary mixer
Answer
Answer: c [Reason:] Double cone mixer is used when one of the components is very less in quantity. This mixer is used to mix items in savory or a snack item.
12. Which of the following is true with respect to mixing operations in the food industry?
a) Ice creams
b) Confectionery products
c) Chlorinated waters
d) All of the mentioned
Answer
Answer: d [Reason:] Ice creams are made by mixing air with aqueous cream mixture. Confectionery products are made by converting oil into semi-solid fat. Chlorinated waters are obtained by physical absorption. Theses help in disinfection purposes.