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This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Clays are what type of binders?(a) Organic(b) Patented(c) Inorganic(d) Other binders |
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Answer» The correct option is (c) Inorganic Best explanation: Clay binders come under the category of inorganic binders. Clay binders are basically known to provide the casts with some good amount of binding properties and optimum moisture contents. |
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| 2. |
Foundry sand is found in which part of Maharashtra?(a) Satara(b) Mumbai(c) Nagpur(d) Nasik |
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Answer» Correct option is (a) Satara The explanation is: Foundry sand is available in Maharashtra, but it is not available in all parts of the state. It is found only in the parts of Satara. |
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| 3. |
What is the amount of sea coal needed in cast irons for small casting moulding sands?(a) 1%(b) 2%(c) 3%(d) 4% |
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Answer» The correct answer is (a) 1% Easiest explanation: In bonding of substances, an extremely small quantity of sea coal is also needed. Sea coal is used for surface appearance improvement. It is used about 1% in cast iron moulding sands for small castings. |
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| 4. |
A voltage source connected in series with a resistor can be converted to a?(a) Current source in series with a resistor(b) Current source in parallel with a resistor(c) Voltage source in parallel with a resistor(d) Cannot be modified |
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Answer» Correct choice is (b) Current source in parallel with a resistor To elaborate: A voltage source connected in series can be converted to a current source connected in parallel using the relation obtained from Ohm’s law, that is V=IR. This equation shows that a voltage source connected in series has the same impact as a current source connected in parallel. |
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| 5. |
Foundry sands cannot be obtained in which of the following states?(a) Uttar Pradesh(b) Punjab(c) Orissa(d) Bihar |
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Answer» The correct choice is (d) Bihar The best explanation: Foundry sand is found to be available in many parts of India like Uttar Pradesh, Punjab and Orissa, but it is not available in the state of Bihar. |
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| 6. |
Which of the following chemical compound, is the most common flux added to the charge in a cupola furnace?(a) Coke(b) Methane(c) Carbon dioxide(d) Limestone |
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Answer» Right choice is (d) Limestone The explanation: Limestone (CaCO3) is used as Flux in cupola furnace in a proportion of about 2-4% of the metal charge. |
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| 7. |
Which sand is generally used repetitively for mould making?(a) Silica sand(b) Zircon(c) Olivine(d) Dolomite |
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Answer» Correct option is (a) Silica sand Best explanation: Silica sand has this as one of its advantages, that it can be used again and again for making moulds. This repetitive use of silica sand makes production even more inexpensive. |
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| 8. |
At what temperature is pitch distilled from soft coals?(a) 400°F(b) 500°F(c) 600°F(d) 700°F |
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Answer» Correct answer is (c) 600°F To elaborate: For pitch distillation of soft coals, a decently high temperature level has to be attained. From soft coal, pitch is distilled at a temperature of around 600°F and a by-product called Asphalt is produced. |
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| 9. |
Pitch maybe used up to what percent?(a) 1%(b) 2%(c) 3%(d) 4% |
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Answer» The correct choice is (b) 2% To explain: Pitch distillation of soft coals plays a vital role in bonding theory. Pitch is used for getting a good surface finish on iron casts. These pitches generally are used up to be to 2%. |
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| 10. |
How much should fuel oil be added to increase the moulding ability of sand?(a) 0.01% – 0.1%(b) 0.02% – 0.2%(c) 0.03% – 0.3%(d) 0.04% – 0.4% |
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Answer» Correct choice is (a) 0.01% – 0.1% Explanation: Fuel oils are known to have great properties in them. Fuel oils are helpful in adding to the increase of the moulding ability of sand. It can be added in the range of 0.01% to 0.1%. |
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| 11. |
Which of the following percent of carbon is correct for Eutectoid steel (at 723^oC in Fe3-C diag)?(a) 0.05%(b) 0.5%(c) 0.6%(d) 0.8% |
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Answer» Right choice is (d) 0.8% To explain I would say: At 723^oC in Fe3C diagram the transformation change takes place. The carbon content at this point is 0.8% and is called as eutectoid steel. |
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| 12. |
Find the equivalent resistance between X and Y.(a) 3.33 ohm(b) 4.34 ohm(c) 5.65 ohm(d) 2.38 ohm |
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Answer» Correct option is (d) 2.38 ohm For explanation: The 3 2ohm resistors are connected in star, changing them to delta, we have R1=R2=R3= 2+2+2*2/2=6 ohm. The 3 6ohm resistors are connected in parallel to the 10 ohm 5 ohm and 10ohm resistors respectively. This network can be further reduced to a network consisting of a 3.75ohm and 2.73ohm resistor connected in series whose resultant is intern connected in parallel to the 3.75 ohm resistor. |
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| 13. |
Why should the moulding sand be porous?(a) For gases to enter(b) For gases to escape(c) For water to enter(d) For water to escape |
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Answer» Correct answer is (b) For gases to escape To explain: A moulding sand is the one in which, the sand is known to have holes in it and also it is known for holding some amount of moisture content. A moulding should be having pores and should be permeable so that the gases have a free path for escaping. |
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| 14. |
In the green sand moulding of steel casting, what is the dextrine percentage composition?(a) 0.5%(b) 1.5%(c) 2.5%(d) 3.5% |
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Answer» The correct choice is (a) 0.5% The best explanation: In green sand mouldings of steel castings, the dextrine percentage composition is calculated to be 0.5% and the bentonite percentage in the same green sand is higher than dextrin by around 3%. |
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| 15. |
How can we calculate the solidification time?(a) Shrinkage volume consideration method(b) Modulus method(c) Novel research method(d) Chvorinov’s rule |
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Answer» Right option is (d) Chvorinov’s rule The explanation is: Shrinkage volume consideration method, Modulus method, and Novel research method are used for riser design. For calculation of solidification time, Chvorinov’s Rule is used. The Same rule can be modified for riser design called as Caine’s method. |
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| 16. |
Which of the following methods is used for the determination of optimum riser size?(a) RMS method(b) Modulus method(c) Finn method(d) Ring method |
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Answer» Correct option is (b) Modulus method Easy explanation: For the finding of optimum riser size, modulus method is very easy to take in action, and empirically it is also established that if the modulus of the riser exceeds the modulus of the casting by a factor of 1.2, then the feeding during the solidification part of the casting would be satisfactory. |
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| 17. |
Which of the following components of soil are acts as chemical sponges in the soil?(a) Clay minerals(b) Silica(c) Sodium(d) Potassium |
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Answer» Correct answer is (a) Clay minerals The best I can explain: Clay minerals are quite stable and are an important part of the soil. Clay minerals are also called as chemical sponges which basically hold water content and dissolved nutrients from other mineral particles. This results due to the presence of unstable electric charges on the surface of clay particles, in which opposite charges attract to each other. |
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| 18. |
What does the clay particle absorb in electrostatic bonding theory?(a) Complete water(b) H^+ ions(c) OH^–ions(d) Sand grains |
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Answer» Correct option is (c) OH^–ions Best explanation: The OH^– ions are basically the base ions. The clay particles in electrostatic bonding theory, absorb the OH^– ions because of the not satisfied valence bond. |
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| 19. |
In which of the following bonding theory, water molecules break down to form H+ and OH- ions?(a) Electrostatic bonding theory(b) Hot strength theory(c) Surface tension theory(d) Block and wedge theory |
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Answer» Correct option is (a) Electrostatic bonding theory Explanation: In electrostatic bonding theory, water is mixed in clay and sand grains, these water molecules then break into H^+ ions and OH^– ions. |
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| 20. |
Buffer amplifier converts ____________(a) low impedance signals to high impedance signals(b) high impedance signals to low impedance signals(c) ac impedance signals to dc impedance signals(d) dc impedance signals to ac impedance signals |
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Answer» Right option is (b) high impedance signals to low impedance signals The best I can explain: Noise is typically generated from motion artefacts and power line interference. A common solution used to suppress noise in dry electrode signals is a buffer amplifier. A buffer amplifies is essentially an impedance converter, that converts high impedance signals to low impedance signals. |
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| 21. |
On increasing the distance between the plates of a variable capacitor, the displacement- capacitance characteristics changes _______(a) proportionally(b) linearly(c) exceptionally(d) hyperbolically |
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Answer» The correct choice is (d) hyperbolically The explanation: By moving one plate of the capacitor with respect to the other, the capacitance will vary inversely with respect to the plate separation. This will give a hyperbolic displacement capacitance characteristic. This is how variable capacitance is employed as displacement transducers. |
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| 22. |
Which of the following statement is true?(a) It is possible to pour only ferrous metals for casting in Nobake process(b) It is possible to pour only non-ferrous metals for casting in Nobake process(c) Both ferrous as well as non ferrous metals can be used for casting through Nobake process(d) Neither ferrous, nor non-ferrous metals are used for casting in nobake process |
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Answer» Correct answer is (c) Both ferrous as well as non ferrous metals can be used for casting through Nobake process Best explanation: Both ferrous as well as non-ferrous metals are compatible with mould made though Nobake process. |
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| 23. |
Which of the following ways can use for stopping the rapid solidification of the molten metal in the mould?(a) By having the mould of high permeability(b) By making a uniform flow of molten metal(c) By creating high pressure on the molten metal(d) By using too much superheat |
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Answer» The correct option is (d) By using too much superheat The explanation: When the liquid metal is poured very slowly, then the time taken to fill up the mould is rather long and the solidification may start even before the mould has been completely filled up. This can be avoided by using too much superheat, but this creates the gas solubility problem which is not good for castings. |
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| 24. |
Which of the following is a passive device?(a) Transistor(b) Rectifier(c) Capacitor(d) Vaccuum Tubes |
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Answer» Right choice is (c) Capacitor To explain I would say: Capacitor is a passive device as it consumes power rest all generate power so, they are active devices. |
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| 25. |
Electric field terminates at ________(a) Positive charge(b) Negative charge(c) Neither positive nor negative(d) Both positive and negative |
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Answer» Correct choice is (b) Negative charge To explain: Electric field originates at the positive charge and terminates at the negative charge. The conventional direction of the field is from positive to negative. |
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| 26. |
What is the function of slag hole in a cupola furnace?(a) To tap the slag generated(b) To generate the slag(c) To allow outflow of gases(d) All of the mentioned |
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Answer» Right option is (a) To tap the slag generated Explanation: Slag hole is a tapping hole in a cupola furnace. Through which slag generated during the melting process is tapped. |
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| 27. |
Which of the following is a key parameter when we design a riser using Novel research method?(a) Modulus(b) Freezing ratio(c) Shape factor(d) Shrinkage volume |
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Answer» Right answer is (c) Shape factor To explain: Modulus is used for designing of riser using modulus method. The freezing ratio is a key parameter when we design riser using Caine’s method. Shrinkage volume is used when we use the shrinkage volume method. For Novel research method, we use shape factor and corresponding to this we find Y from casting databook which is the ratio of the volume of casting to the volume of the riser. |
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| 28. |
Which of the below is not an instrument used to set right angles?(a) Cross staff(b) Site square(c) Optical staff(d) Prism square |
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Answer» Right option is (c) Optical staff Best explanation: There is no instrument like an optical staff. Optical square is an instrument which consists of circular box with three slits. Cross staff is a frame of the box mounted on a pole. Prism square is an advanced version of an optical square. Site square consists of two telescopes set at 90^os. |
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| 29. |
In the case of coldbox core _____________(a) The core mix is heat treated in order to cure it(b) Core mix immediately gets cured after sand is blown(c) Time is given to the core mix to be cure(d) Cold water is poured onto the core mix |
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Answer» Correct option is (c) Time is given to the core mix to be cure The explanation is: Due to high production rates, the coldbox are left alone to cure by itself after the sand is blown into the corebox. |
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| 30. |
What does a mould having adequate green strength, does not have?(a) Ability to retain its shape(b) Ability not to get distorted(c) Ability not to collapse(d) Ability to retain hardness |
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Answer» Right choice is (d) Ability to retain hardness The best explanation: For a mould to be having an adequate amount of green strength, it must have retaining ability or the ability to get distorted or to collapse. A mould having adequate green strength does not have the ability to retain hardness. |
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| 31. |
Why is Velocity of a fluid in contact with any solid surface is zero?(a) Due to cohesive forces in the fluid particles(b) Due to low velocity of fluid(c) Due to no slip condition(d) Due to high intermolecular forces between the fluid particles |
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Answer» Correct answer is (c) Due to no slip condition The explanation is: Velocity of a liquid metal in the sprue and the gate is not uniform across the cross-sections. It is maximum at the axis of the conduit and zero at the solid surface due to high adhesive bonding between the surface and the fluid particles, which is responsible for viscosity and results in no slip condition. |
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| 32. |
When would dross and slag tend to float on the metal surface?(a) When pouring basins are doubled(b) When pouring basins are made large(c) When pouring basins are made small(d) When pouring basins are removed |
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Answer» Correct choice is (b) When pouring basins are made large Explanation: The metal could be stopped from entering the sprue, and would cause the dross and slag to float on the metal surface, when the pouring basins are made large. |
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| 33. |
What is the voltage across a capacitor at the time of switching, that is, when t=0?(a) Infinity(b) 0V(c) Cannot be determined(d) 1V |
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Answer» Right option is (b) 0V Explanation: At the time of switching, when t=0, the capacitor acts as a short circuit. The voltage across a short is always equal to zero hence the voltage across the capacitor is equal to zero. |
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| 34. |
Which shaped lines indicate the presence of a ridge?(a) V-shaped(b) U-shaped(c) L-shaped(d) S-shaped |
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Answer» The correct answer is (b) U-shaped Easiest explanation: The contour line with U-shape, which has convexity towards a lower ground shows the presence of a ridge. |
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| 35. |
Calculate the charge in the 2F capacitor.(a) 200C(b) 100C(c) 300C(d) 400C |
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Answer» Correct option is (a) 200C To explain I would say: Since the capacitors are connected in parallel, the voltage across each is the same, it does not get divided. Q = CV = 2*100 = 200C. |
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| 36. |
What will be the feeding distance (in inches) without using chill for a plate of thickness T?(a) 4.5√T + 2(b) 4.5√T(c) 6√T+2(d) 6√T |
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Answer» Right answer is (b) 4.5√T For explanation: Feeding distance will be equal to 4.5√T + 2 if we are using chill for a plate. For a bar, feeding distance will be 6√T without chill and 6√T +2 with chill. Thus, feeding distance will be equal to 4.5√T if we are not using chill during casting a plate. |
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| 37. |
Why is sand bed prepared for melting of metal in Cupola furnace?(a) It provides a refractory bottom(b) It soaks the moisture from the metal(c) It conducts the heat faster and uniformly(d) None of the mentioned |
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Answer» Right choice is (a) It provides a refractory bottom Easy explanation: A sand bed needs to be prepared because it provides a necessary refractory bottom for molten metal and coke. |
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| 38. |
Which of the following is bentonite?(a) Kaolinite(b) Sodium Montmorillonite(c) Illite(d) Limonite |
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Answer» The correct choice is (b) Sodium Montmorillonite The explanation is: Bentonite sands are one of the most useful additive in casting sands, as it helps in enhancing its properties. Bentonite is classified into 2 types, namely, Sodium montmorillonite and Calcium montmorillonite. |
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| 39. |
Which of the following would not happen if hot strength is not enough?(a) The mould may get hardened(b) The mould may get enlarged(c) The mould may get eroded(d) The mould may crack |
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Answer» The correct option is (a) The mould may get hardened Best explanation: If there is not an adequate amount of hot strength provided, then the mould may get enlarged, the mould may get eroded and the mould may crack, but the mould will not get hardened. |
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| 40. |
Which of the following is not used as binders for mould materials?(a) Bentonite(b) Kaolinite(c) Backelite(d) Illite |
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Answer» The correct answer is (c) Backelite Explanation: Backelite is a material which increases hardness beyond a limit which is acceptable for mold materials as well as its deformation takes place too early as plastic deformation. Hence, it is not used as a binder. |
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| 41. |
Core oil and binders change their chemical properties at what temperature?(a) 200°F – 300°F(b) 300°F – 400°F(c) 400°F – 500°F(d) 500°F – 600°F |
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Answer» Right option is (c) 400°F – 500°F To explain I would say: Whenever any material is heated to a temperature high for its properties, there is a change in its chemical and physical aspects seen. Core oils and organic binders used in backing the core, change their physical properties at 400°F – 500°F. |
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| 42. |
Phosphorus is added to steel mold for which of the following reason?(a) It increases strength and hardness of steel(b) It increases refractoriness of steel(c) It increases porosity of steel(d) It increases finishing of steel |
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Answer» The correct choice is (a) It increases strength and hardness of steel Best explanation: Phosphorus has the ability to increase strength and hardness of steel material when added to it in the right compostion (2-4%). |
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| 43. |
How many types of wastewater treatment plants are there based on the type of wastewater?(a) 5(b) 4(c) 2(d) 3 |
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Answer» Right answer is (d) 3 Explanation: There are 3 types- Sewage, Industrial and Agricultural. |
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| 44. |
Which of the following members of clay minerals is formed by the decompositions of micas?(a) Chlorite(b) Illite(c) Kaolinite(d) Vermiculite |
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Answer» The correct choice is (d) Vermiculite Easiest explanation: Vermiculite is a very important and essential member of clay minerals which is normally formed by the decompositions of micas and occurs as completely large crystals of mica like appearance. It has a layer structure which basically consists of water particles and exchangeable cations which are mainly magnesium ions. |
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| 45. |
In the green sand moulding of steel casting, what is the moisture percentage composition?(a) 1% – 2%(b) 2% – 3%(c) 3% -4%(d) 4% – 5% |
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Answer» Correct answer is (c) 3% -4% To elaborate: In green sand mouldings of steel castings, the moisture percentage composition is calculated to be 3%- 4% and the amount of bentonite present in the same green sand is around 3.5%. |
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| 46. |
What is the melting point of Olivin?(a) 3450°F – 4620°F(b) 3200°F – 3450°F(c) 3100°F – 3220°F(d) 3400°F – 3620°F |
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Answer» Right option is (b) 3200°F – 3450°F Best explanation: According to the properties of granular refractories, Olivin has a melting point temperature of 3200°F to 3450°F. Olivin is one of the materials which do not change its state at low temperatures. |
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| 47. |
What is a function of a riser in a sand casting?(a) Provide good mobility to the molten metal(b) Prevent cavities due to shrinkage(c) To develop holes or hollow cavities in the casting(d) To provide differential cooling rates in specific areas of the casting |
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Answer» The correct choice is (b) Prevent cavities due to shrinkage Explanation: The risers also known as feeders are used to decrease the phenomena of shrinkage during solidification of the molten metal. |
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| 48. |
Pattern cannot be constructed out of which of the following materials?(a) Wood(b) Wax(c) Oil(d) Metal |
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Answer» Right option is (c) Oil Easiest explanation: Oil is used as fuels for melting metals in various furnaces. It cannot be used for constructing a pattern, while all other materials are used for making patterns. |
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| 49. |
By how much percentage does the volume increase when the moisture content is 5-10%?(a) 10-20%(b) 20-40%(c) 30-40%(d) 20-30% |
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Answer» Correct choice is (b) 20-40% To explain: The studies on bulking have shown this result. It is visible in the graphical representation of bulking also. |
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| 50. |
The loss in biodiversity is not attributed to:(a) Explosion in the human population(b) Transforming earth’s surface(c) Destruction of natural habitats(d) Use of sustainable products |
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Answer» Right answer is (d) Use of sustainable products To explain: The ever-exploding increase in human population leads to the consumption of resources and exploitation of the earth’s surface. This results in the destruction of natural habitats and ecosystems. The use of sustainable alternatives is a step towards conservation. |
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