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Multiple choice question for engineering

Set 1

1. Which of the following cannot be operated through cupola furnace?
a) Cast irons
b) Copper alloys
c) Bronze
d) Zinc

View Answer

Answer: d [Reason:] Among the following, zinc cannot be operated through cupola furnace, whereas the irons, copper base alloys and some kinds of bronzes are operated using a cupola furnace.

2. Which instrument is attached at the top of cupola?
a) Air blast
b) Coke bed
c) Wind box
d) Spark arrester

View Answer

Answer: d [Reason:] A spark arrester is positioned at the top of the cupola furnace, below which starts the stack zone, or the cupola furnace is open at the top.

3. What should the height of a cupola furnace?
a) 5m
b) 6m
c) 7m
d) 8m

View Answer

Answer: b [Reason:] The height of a cupola furnace commonly about 6m, whereas the cupolettes have a height of approximately 2.5m to 4m. There is a spark arrester attached to the top of the cupola.

4. The bottom of cupola is made up of which material?
a) Pig iron
b) Cast iron
c) White iron
d) Grey iron

View Answer

Answer: b [Reason:] The bottom being the legs of cupola are made up of cast irons, also the doors for bottom opening of cupola are made of cast iron only.

5. The volume of air passing in cupola is calculated using which device?
a) Area meter
b) Surface meter
c) Volume meter
d) Pressure meter

View Answer

Answer: c [Reason:] The air flows in the cupola, passing through the combustion zone. This volume of air can be calculated using a device called as Volume meter.

6. What is the maximum capacity of a cupolette?
a) 0.25 ton
b) 0.5 ton
c) 0.75 ton
d) 1 ton

View Answer

Answer: d [Reason:] Small cupolas are called as cupolettes. The capacity of a cupolette ranges from 0.5 ton to 1 ton. These cupoletes have a height of about 4.5 meters to 6 meters.

7. Cupola produces metal of uniform quality.
a) True
b) False

View Answer

Answer: b [Reason:] Cupola does not have a specific time duration of operation. Hence, there is no uniform quality in the production of metal.

8. What is the purpose of auxiliary tuyeres?
a) Raise solidification efficiency
b) Drop solidification efficiency
c) Raise melting efficiency
d) Drop melting efficiency

View Answer

Answer: c [Reason:] Auxiliary tuyeres are basically used for providing to increase the melting efficiency. They are fitted in one or more number of rows.

9. For how much time is the cupola fired before pouring?
a) 2 hours
b) 3 hours
c) 4 hours
d) 5 hours

View Answer

Answer: b [Reason:] The process of lighting is starting the cupola and firing it for about 3 hours, a little before the metal is needed for pouring.

10. A cupola is cylindrical in shape.
a) True
b) False

View Answer

Answer: a [Reason:] A cupola is basically a cylindrical metal shell which is either welded or riveted to the boiler plate. It is mainly open at the top.

Set 2

1. What is the amount of pig iron in a cupola charge?
a) 10% – 20%
b) 10% – 30%
c) 30% – 40%
d) 20% – 45%

View Answer

Answer: b [Reason:] The amount of pig iron present inside a cupola charge varies from 10% to 30%, where the exact amount depends upon the type of iron that is used.

2. How much steel scrap is present in refined irons?
a) More than 25%
b) More than 60%
c) More than 50%
d) More than 95%

View Answer

Answer: c [Reason:] Refined irons are considered to be the second best source of high carbon material. The steel scrap which is present in refined irons is a little more than 50%.

3. What is the main source of high carbon steel material?
a) Pig iron
b) Cast iron
c) White iron
d) Steel scrap

View Answer

Answer: a [Reason:] Steel scrap is a big source for high carbon steel materials, but is considered as the second biggest source. The main source for high carbon steel materials is pig iron.

4. According to the UK standards, in general, what is the diameter of the iron bar which is used in iron castings?
a) 18mm
b) 12mm
c) 30mm
d) 43mm

View Answer

Answer: c

5. What is the tensile strength of grade 220 iron?
a) 220 Dyne/mm2
b) 220 N/m2
c) 220 N/mm2
d) 220 Dyne/cm2

View Answer

Answer: c [Reason:] According to the standards of UK, the castings are made in a specified grade of iron. Hence, iron having a grade of 220, is equivalent to iron having a tensile strength of 220 N/mm2.

6. The sulphur content in acid-cupola operation does not depend on which of the following factors?
a) Quantity of coke
b) Slag basicity
c) Tensile strength of the steel
d) Quantity of steel

View Answer

Answer: c [Reason:] In the acid-cupola reaction, the sulphur content is always increased. This increase in the sulphur content depends on quantity of coke, quantity of steel, the slag basicity, but not the tensile strength of steel.

7. What should be the lowest sulphur pick-up in the acid-cupola reaction?
a) 10%
b) 13%
c) 18%
d) 21%

View Answer

Answer: a [Reason:] There is no such method in existence which will be able to tell us the amount of sulphur pick-up. But, the lowest amount of sulphur pick-up in acid-cupola reaction should not be more than 10%.

8. What should be the highest sulphur pick-up in the acid-cupola reaction?
a) 90%
b) 63%
c) 68%
d) 51%

View Answer

Answer: a [Reason:] There is no such way by which one may be able to identify the amount of sulphur pick-up. But, the highest amount of sulphur pick-up in acid-cupola reaction should not be more than 80% to 90%.

9. Close temperature control is easy to maintain in cupola.
a) True
b) False

View Answer

Answer: b [Reason:] It is considered among one of the limitations of cupola, that the close temperature control is a little difficult to maintain in the operation of a cupola.

10. Cupola operation is inexpensive.
a) True
b) False

View Answer

Answer: a [Reason:] Cupola operations are considered to be having a simple design and its construction is also simple. The initial cost is low when compared to other furnaces, hence the operation is considered to be an inexpensive one.

Set 3

1. Which material is used for making the roof of an acid lined furnace?
a) Silica
b) Dolomite
c) Magnesite
d) Carbon tetrachloride

View Answer

Answer: a [Reason:] A very heavy steel shell is equipped in making the roof, with the help of refractory bricks. To this, silica is added when the furnace is acid lined.

2. Which material is used for making the roof of an acid lined furnace?
a) Silica
b) Hydrogen peroxide
c) Carbon tetrachloride
d) Magnesite

View Answer

Answer: d

3. What is the minimum transformer power supply needed by the direct arc furnace?
a) 600 kVA
b) 700 kVA
c) 800 kVA
d) 900 kVA

View Answer

Answer: c [Reason:] For the remelting of steel, a high amount of power supply is needed by the direct arc furnace. The minimum transformer power supply needed by the furnace is 800 kVA.

4. What is the capacity of a largest direct arc furnace?
a) 110 tons
b) 115 tons
c) 125 tons
d) 140 tons

View Answer

Answer: c [Reason:] The direct arc furnace is widely used in the steel foundries for the remelting unit. The largest direct arc furnace is found to have a capacity of 125 tons for remelting steel.

5. What is the maximum transformer power supply needed by the direct arc furnace?
a) 35,000 kVA
b) 40,000 kVA
c) 45,000 kVA
d) 50,000 kVA

View Answer

Answer: b

6. What is typically the diameter of a direct arc furnace?
a) Up to 5m
b) Up to 6m
c) Up to 7m
d) Up to 8m

View Answer

Answer: b [Reason:] The direct arc furnace is widely used in the steel foundries for remelting steels of various compositions. In general, the diameter of a direct arc furnace is found to be only up to 6 meters.

7. What would be the amount of current carried by the electrode for a direct arc furnace having capacity 50 tons?
a) 25 kilo amperes
b) 25 mega amperes
c) 25 micro amperes
d) 25 nano amperes

View Answer

Answer: a [Reason:] For a direct arc furnace having a capacity of around 50 tons, the electrode would carry a current of approximately 25,000 amperes, which is 25 kA. These electrodes can be moved upwards and downwards.

8. Roofs of the furnace have a small life.
a) True
b) False

View Answer

Answer: a [Reason:] The roofs of the furnace bear with many damages during the operations. A few spare roofs should always be available, since the roof does not have a very long life.

9. Basic refractories are costlier than acid refractories.
a) True
b) False

View Answer

Answer: a [Reason:] To be operating in a basic refractory, it is advantageous as the inferior scrap can be used for the production of good quality steel. Hence, basic refractories are costlier than acid refractories.

10. How much is the thermal efficiency of a direct arc furnace?
a) 50%
b) 60%
c) 70%
d) 80%

View Answer

Answer: c [Reason:] In a direct arc furnace, the analysis of the melt can be accurately calculated and its efficiency can go as high as up to 70%.

Set 4

1. Which of the following is not a type of developer?
a) Dry powder
b) Water soluble developer
c) Oil soluble developer
d) Water suspendible developer

View Answer

Answer: c [Reason:] Dye penetrant test is one of the methods of non-destructive testing of the components. The application of developer is one of the steps of inspection of dye penetrant test. Oil soluble developer is not a type of developer.

2. For how long is a penetrant allowed to soak in cracks?
a) 5 to 15 minutes
b) 10 to 30 minutes
c) 15 to 35 minutes
d) 20 to 40 minutes

View Answer

Answer: b

3. Penetrants of which colour are not used?
a) Red
b) Blue
c) Green
d) Yellow

View Answer

Answer: a [Reason:] The application of penetrant is one of the steps of inspection of dye penetrant test. It is an important feature that one must take care of, that the penetrant used, must not be of red colour, as defects are identified using red colour.

4. Which of the following is not an excess penetrant remover?
a) Solvent removable
b) Water washable
c) Lipophilic pre-emulsifiable
d) Lipophilic post-emulsifiable

View Answer

Answer: c [Reason:] A penetrant remover material highly depends on the type of material by which the penetrant is made. Among the following, a lipophilic pre-emulsifiable is not a type of excess penetrant remover.

5. Which of the following is not a method of pre-cleaning?
a) Solvent
b) Acid blasting
c) Vapour degreasing
d) Media blasting

View Answer

Answer: b [Reason:] The application of pre-cleaning is one of the steps of inspection of dye penetrant test. Solvent, alkaline, vapour degreasing and media blasting are a few types of pre-cleaning process, but not acid blasting.

6. Which of the following is not a type of penetrant application?
a) Dipping
b) Spraying
c) Brushing
d) Pouring

View Answer

Answer: d [Reason:] The application of penetrant is one of the steps of inspection of dye penetrant test. Among these, dipping, spraying or brushing are different ways by which penetrant can be applied, but not pouring.

7. Which of the following defect is not detected by dye penetrant test?
a) Non-metallic inclusions
b) Leaks
c) Cracks
d) Forging defects

View Answer

Answer: a [Reason:] Dye penetrant test is one of the methods of non-destructive testing of the components. Leaks, cracks and forging defects are some defects which can be identified by using dye penetrant test. But, for detecting non-metallic inclusions, one will have to do a magnaflux test.

8. What is the amount of time taken for blotting?
a) 5 minutes
b) 10 minutes
c) 15 minutes
d) 20 minutes

View Answer

Answer: b [Reason:] The process of inspection is one of the steps of important of dye penetrant test. The operation of inspection begins after the article is allowed to blot for around ten minutes.

9. Only fluorescent dye is used in dye penetrant test.
a) True
b) False

View Answer

Answer: b [Reason:] For the inspection using non-destructive testing, when dye penetrant test is used, there are two types of lights that are used. This type of light which has to be used, depends upon the type of die used, fluorescent or non-fluorescent.

10. Only ultraviolet light is used in dye penetrant test.
a) True
b) False

View Answer

Answer: b

Set 5

1. Eddy current testing does not work below what thickness of materials?
a) 0.1 mm
b) 0.2 mm
c) 0.3 mm
d) 0.4 mm

View Answer

Answer: a [Reason:] It is one of the limitations of eddy current that defects having a thickness larger than required cannot be detected using eddy current method. Conventionally eddy current method cannot detect surface defects below 0.1 mm.

2. Eddy currents are not used for the measure of which of the following properties?
a) Electrical conductivity
b) Magnetic resistivity
c) Hardness
d) Grain size

View Answer

Answer: b [Reason:] The inspection of structures done by eddy current method is based on the principle electromagnetic induction. This method of detecting defects can be used for knowing the measure of electrical conductivity, grain size, hardness and magnetic permeability.

3. Eddy current inspection method cannot be detect which of the following defect?
a) Laps
b) Seams
c) Voids
d) Surface crack

View Answer

Answer: d

4. Small drilled hole was a reference calibration in eddy current testing because it was produced in precise sizes.
a) True
b) False

View Answer

Answer: a [Reason:] For making perfect measurements and calculations, a few artificial defects were tried and a small hole was selected as the standard. The small drilled hole was selected because, it was not just easy to produce, but also, it was produced in precise sizes.

5. What is the heat generated in eddy current operations?
a) VI
b) VIR
c) I2RT
d) I2R

View Answer

Answer: d [Reason:] Eddy current method of inspection and heating techniques is used for metal heating. The heat generated by this method can be given by I2R, I is current and R is the resistance.

6. The signal display of eddy current system does not take place on which of the following media?
a) Oscilloscope
b) Oscillograph
c) Electric tape
d) Magnetic tape

View Answer

Answer: c [Reason:] Eddy current method is used as a non-destructive technique. Most of the times, a magnetic tape is used or a oscilloscope or an oscillograph, but not an electric tape.

7. Multi frequency testing allows to overcome problems in eddy current testing?
a) True
b) False

View Answer

Answer: a [Reason:] It is one of the limitations of eddy current testing that, below a certain thickness of the surface defect, the defect cannot be detected. This particular problem can be overcome by using multifrequency testing.

8. For measuring glue line thickness between aluminium sheets, what should the thickness of the sheet be?
a) 1.2 mm
b) 1.4 mm
c) 1.6 mm
d) 1.8 mm

View Answer

Answer: c [Reason:] For measuring the glue line thickness of aluminium sheets using eddy current method, initially the surface has to be vitally cleaned. The thickness of the aluminium sheet for calculating glue line thickness is 1.6mm.

9. What is the conductivity of a 7075-T6 aluminium sheet with an average thickness of 1.6 mm?
a) 30 IACS
b) 31 IACS
c) 32 IACS
d) 33 IACS

View Answer

Answer: b

10. With an increase in the density of the material who does it affect the power loss in eddy current?
a) Increases
b) Decreases
c) Does not change
d) Not related

View Answer

Answer: b [Reason:] According to the power dissipation formula for eddy currents, power loss experienced is inversely related to the density of the material, that is, with an increase in the density of the material, there is a decrease in the power loss.