McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Uncategorized topics .
| 151. |
Ultra high-speed steels are made of which of the following elements? |
| A. | tungsten and molybdenum |
| B. | chromium and molybdenum |
| C. | vanadium and cobalt |
| D. | molybdenum and cobalt |
| Answer» C. vanadium and cobalt | |
| Explanation: ultra high-speed steels have greater tool lives and greater cutting efficiency. this is due to the addition of vanadium (up to 4%) and cobalt (5% to 12%) along with carbon, chromium, and tungsten. | |
| 152. |
What is the microstructure of Hadfield’s steel? |
| A. | austenite |
| B. | ferrite |
| C. | martensite |
| D. | cementite |
| Answer» A. austenite | |
| Explanation: hadfield’s manganese steels (mangalloy) possess great strength and toughness. its austenite structure is obtained by heating it. this also results in high wear resistance, which finds its applications in bulldozers, crushers, etc. | |
| 153. |
Which of the following is the hardest constituent of steel? |
| A. | ledeburite |
| B. | austenite |
| C. | bainite |
| D. | martensite |
| Answer» D. martensite | |
| Explanation: martensite is the hardest constituent of steel. the primary reasons | |
| 154. |
Iron possesses BCC crystal structure up to (in degree centigrade)? |
| A. | 1539 |
| B. | 768 |
| C. | 910 |
| D. | 1410 |
| Answer» B. 768 | |
| Explanation: pure iron possess either bcc or fcc crystal structure as its temperature is increased from room temperature to its melting point. at room temperature to 910oc, it is having bcc, between 910oc and 1410oc it is having face centered cubic, and from 1410oc to its melting point (1539oc) it returns to its bcc crystal structure. | |
| 155. |
Iron possesses BCC crystal structure above (in degree centigrade)? |
| A. | 1539 |
| B. | 768 |
| C. | 910 |
| D. | 1410 |
| Answer» D. 1410 | |
| Explanation: from 1410oc to its melting point (1539oc) iron is having bcc crystal structure. | |
| 156. |
Which of the following form of iron is magnetic in nature? |
| A. | α |
| B. | δ |
| C. | γ |
| D. | λ |
| Answer» A. α | |
| Explanation: the alpha form of iron is magnetic and stable at all temperatures below 910oc. | |
| 157. |
For steel, which one of the following properties can be enhanced upon annealing? |
| A. | hardness |
| B. | toughness |
| C. | ductility |
| D. | resilience |
| Answer» C. ductility | |
| Explanation: a furnace cooling technique, annealing will enhance the ductility of steel, due to the formation of coarse pearlite. | |
| 158. |
In Annealing, cooling is done in which of the following medium? |
| A. | air |
| B. | water |
| C. | oil |
| D. | furnace |
| Answer» D. furnace | |
| Explanation: in annealing, after solutionising, material is used to furnace cool, means furnace is switched off and the steel sample inside is let cool down. | |
| 159. |
In normalizing, cooling is done in which of the following medium? |
| A. | air |
| B. | water |
| C. | oil |
| D. | furnace |
| Answer» A. air | |
| Explanation: in normalizing, steel is heat treated above its critical temperature, solutionised, and then allowed to cool for a long time by keeping it in air. in steel, it forms fine pearlite, which imparts strength to steel. | |
| 160. |
Mild steel can be converted into high carbons steel by which of the following heat treatment process? |
| A. | annealing |
| B. | normalizing |
| C. | case hardening |
| D. | nitriding |
| Answer» C. case hardening | |
| Explanation: case hardening, also referred as carburizing increases carbon content of steel, thus, imparting hardness to steel. | |
| 161. |
Upon annealing, eutectoid steel converts to which of the following? |
| A. | perlite |
| B. | cementite |
| C. | austenite |
| D. | martensite |
| Answer» A. perlite | |
| Explanation: eutectoid steels upon annealing produces pearlite (coarse pearlite). pearlite is an alternate lamellae of ferrite and cementite. | |
| 162. |
What is Gibbs phase rule for metallurgical system? |
| A. | f = c – 1 – p |
| B. | f = c + 1 – p |
| C. | p + f = c – 2 |
| D. | p + f = c + 2 |
| Answer» B. f = c + 1 – p | |
| Explanation: for metallurgical system pressure has no appreciable effect on phase equilibrium and hence, f = c – p + 1. | |
| 163. |
In a single – component condensed system, if degree of freedom is zero, maximum number of phases that can co – exist |
| A. | 2 |
| B. | 3 |
| C. | 0 |
| D. | 1 |
| Answer» A. 2 | |
| Explanation: given f = 0 then p = c + 1, c = 1 | |
| 164. |
What is degree of freedom when two phases co – exist? |
| A. | 2 |
| B. | 3 |
| C. | 0 |
| D. | 1 |
| Answer» D. 1 | |
| Explanation: f = c + 1 – p f = 3 – p (c = 2) | |
| 165. |
What is degree of freedom when three phases co – exist? |
| A. | 2 |
| B. | 3 |
| C. | 0 |
| D. | 1 |
| Answer» C. 0 | |
| Explanation: f = c + 1 – p f = 3 – p (c = 2) | |
| 166. |
When α, L and β phase fields touch the isotherm line what are the respective phase compositions? |
| A. | 8.0 wt%, 71.9 wt%, 91.2 wt% of ag |
| B. | 8.0 wt%, 91.2 wt%, 71.9 wt% of ag |
| C. | 71.9 wt%, 91.2 wt%, 8.0 wt% of ag |
| D. | 91.2 wt%, 8.0 wt%, 71.9 wt% of ag |
| Answer» A. 8.0 wt%, 71.9 wt%, 91.2 wt% of ag | |
| Explanation: for binary systems, when three phases are present, there will be f = 0, so composition is fixed. | |
| 167. |
For binary alloy consisting of three phases of non – equilibrium one, What will be the temperature of these phases? |
| A. | different |
| B. | constant |
| C. | same |
| D. | two of them will be with one temperature |
| Answer» C. same | |
| Explanation: one use of the gibbs phase rule is in analyzing for non – equilibrium conditions by analyzing with above method we come to know (under these circumstances, three phases will exist only at a single temperature). | |
| 168. |
What does Gibb’s phase rule state? |
| A. | p+f=c-1 |
| B. | p+f=c+1 |
| C. | p+f=c-2 |
| D. | p+f=c+2 |
| Answer» D. p+f=c+2 | |
| Explanation: the above phase rule is a formula that gives the condition for finding the number of phases in a system. this phase rule can be applied to both condensed as well as normal systems. | |
| 169. |
What is the point at which all the three phases of a system exist? |
| A. | triple point |
| B. | sublimation point |
| C. | vapor point |
| D. | eutectic point |
| Answer» A. triple point | |
| Explanation: since at the triple point, the degree of freedom is zero (that is invariant reaction takes place at that point), therefore according to phase rule, f=c-p+2. | |
| 170. |
Liquid phase exists for all compositions above region. |
| A. | eutectic region |
| B. | equilibrium region |
| C. | isometric region |
| D. | sublimation region |
| Answer» C. isometric region | |
| Explanation: in a phase region above the eutectic point, both the solid and liquid phases exist together where the region is bi variant and this region is called isometric region. here the region has 2 degrees of freedom. | |
| 171. |
Select the wrong statements from the following statements with respect to a phase diagram. |
| A. | gives information about concentration |
| B. | gives information about solubility |
| C. | gives information on melting and boiling points |
| D. | gives information on relative concentration |
| Answer» D. gives information on relative concentration | |
| Explanation: a phase diagram gives information only on the concentration of species, their solubility rate, degree of freedom and other physical properties. it does not explain about transformation rates and relative concentration (relative concentration=total concentration/equilibrium concentration). | |
| 172. |
Select a non-homogeneous system from the following. |
| A. | salt solution |
| B. | sugar solution |
| C. | glucose in water |
| D. | saturated solution of nacl |
| Answer» D. saturated solution of nacl | |
| Explanation: a homogeneous mixture is one which is miscible completely with one another. in any saturated solution, when the amount of solute reaches more than a critical point, then the solution becomes heterogeneous. | |
| 173. |
Select the odd statement with respect to a phase reaction. |
| A. | saturated solution |
| B. | equilibrium solution |
| C. | concentric solution |
| D. | amorphous solution |
| Answer» A. saturated solution | |
| Explanation: a terminal solution, an intermediate solution, an equilibrium solution and concentric solutions, are the ones which take part in a phase reaction. on the other hand, a saturated solution is involved in the lever system. | |
| 174. |
Which of the following is the formula for condense phase rule? |
| A. | f=c-p+2 |
| B. | f=c-p+1 |
| C. | f=c+p-2 |
| D. | f=c+p-1 |
| Answer» B. f=c-p+1 | |
| Explanation: in a condensed phase rule system, the phases are represented in three dimension which is not suitable for graphic purposes and hence the pressure is considered to be zero (this is helpful in drawing 2d images). hence the formula reduces to f=c- p+2. | |
| 175. |
Under what condition, will we get a stable phase diagram? |
| A. | solid + liquid |
| B. | solid + vapor |
| C. | liquid + vapor |
| D. | liquid + solid |
| Answer» A. solid + liquid | |
| Explanation: according to equilibrium mixture ration, an appropriate ratio of 1:10 parts of solid and liquid along with an aqueous solution will give a stable phase product. | |
| 176. |
Thermal analysis is defined as |
| A. | measurement of concentration of materials as a function of temperature |
| B. | measurement of solubility of materials as a function of temperature |
| C. | measurement of physical properties as a function of temperature |
| D. | measurement of line positions of crystals as a function of temperature |
| Answer» C. measurement of physical properties as a function of temperature | |
| Explanation: thermal analysis is defined as the measurement of physical and chemical properties of materials as a function of temperature. in practice, however the term thermal analysis is used to cover certain specific properties only. these are enthalpy, heat capacity, mass and coefficient thermal expansion. | |
| 177. |
What are the two main techniques for thermal analysis? |
| A. | ftg and dgg |
| B. | msp and fct |
| C. | tga and dta |
| D. | tsa and dgf |
| Answer» C. tga and dta | |
| Explanation: the two main thermal analysis techniques are thermogravimetric analysis known as tga which measures the change in weight with temperature and differential thermal analysis known as dta which detects changes in heat content. | |
| 178. |
Dilatometry is also known as by which of the following names? |
| A. | tga |
| B. | dta |
| C. | dsc |
| D. | tma |
| Answer» D. tma | |
| Explanation: a fourth thermal analysis technique is dilatometry in which the change in linear dimension of a sample as a function of temperature is recorded. recently it has acquired a new name, thermomechanical analysis (tma). | |
| 179. |
In thermogravimetric analysis, the result obtained appear as a |
| A. | continuous chart |
| B. | continuous parabola |
| C. | continuous circular positions |
| D. | discontinuous chart |
| Answer» A. continuous chart | |
| Explanation: thermogravimetric is a technique for measuring the change in weight of a substance as a function of temperature or time, the result usually appears a continuous chart record, a schematic, typical, single step decomposition reaction. | |
| 180. |
Under conditions of heating, decomposition usually take place in thermogravimetry. Fill up the suitable option from the choices given below. |
| A. | first order |
| B. | second order |
| C. | third order |
| D. | dynamic |
| Answer» D. dynamic | |
| Explanation: in thermogravimetric analysis (tga), decomposition usually take place under dynamic heating conditions over a range of temperature ti to tf and a second constant weight plateau is then observed above tf, which corresponds to the weight of the residue wf. | |
| 181. |
The Ti and Tf temperature depends on which of the following factor? |
| A. | cooling rate |
| B. | mechanical property of the material |
| C. | thermal expansion coefficient |
| D. | atmosphere above the sample |
| Answer» D. atmosphere above the sample | |
| Explanation: initial and final temperature ti, tf depends on variables such as heating rate, the nature of the solid (e.g. its particle size) and the atmosphere above the sample. the effect of the atmosphere can be dramatic. | |
| 182. |
What is the definition of a lower critical temperature? |
| A. | the minimum temperature at which equilibrium is achieved |
| B. | the lowest temperature at which two components will attain vapor state |
| C. | the lowest temperature at which two components sublimates |
| D. | the lowest temperature at which two components form a mixture |
| Answer» A. the minimum temperature at which equilibrium is achieved | |
| Explanation: the lower critical solution temperature is the lowest temperature at which two components are insoluble and attains equilibrium. conversely, the upper critical solution temperature is the highest temperature at which two components are soluble as single phase. | |
| 183. |
With reference to a two component system, a vapor line indicates |
| A. | a region where the temperature and pressure remains stable |
| B. | a region where the solubility remains constant |
| C. | an area below which components do not mingle |
| D. | an area above which both the components mingle to form a single mixture |
| Answer» A. a region where the temperature and pressure remains stable | |
| Explanation: a vapor line is another name for an isotherm. it represents constant temperature and constant pressure relation at which the equilibrium is obtained. a vapor line helps in finding out equilibrium concentrations. | |
| 184. |
With reference to a two component system, an isobar indicates |
| A. | a region where the temperature remains constant |
| B. | an area below phase end products remains |
| C. | an area above which only the liquid vapors remains |
| D. | a region where the composition lies in equilibrium |
| Answer» D. a region where the composition lies in equilibrium | |
| Explanation: an isobar is a line that indicates a region where the composition remains constant and in the equilibrium state. in a two component solid-liquid system, it is drawn vertically covering a wide range of temperatures. | |
| 185. |
Which of the following statements is not true for a system that has reached the eutectic temperature? |
| A. | the system is a open system |
| B. | the system is a miscible fluid |
| C. | components lie in liquid state |
| D. | a region between sublimation and eutectic curve lies stable |
| Answer» A. the system is a open system | |
| Explanation: the eutectic temperature is achieved by heating a liquid in the point where the density of the liquid state is equal to the density of the vapor state. here, the interface between the liquid and vapor vanishes resulting in a miscible fluid. this can only occur in a closed system (otherwise the vapor would escape into the surroundings). | |
| 186. |
Which of the following statements are correct about the equilibrium point on a two component system? |
| A. | all the compounds are liquid |
| B. | the boiling point of the mixture is less than the boiling points of the individual compounds |
| C. | the degree of freedom is 0 |
| D. | invariant reaction takes place |
| Answer» B. the boiling point of the mixture is less than the boiling points of the individual compounds | |
| Explanation: the eutectic point on a phase diagram is a point at which the mixture boils at a temperature lower than that of the pure substances. the substance attains equilibrium state. | |
| 187. |
During metastable state, the size of the particle |
| A. | increases |
| B. | decreases |
| C. | won’t change |
| D. | not related |
| Answer» A. increases | |
| Explanation: since for a system to be in equilibrium condition, its size automatically increases by mond’s effect which is why the particle’s size increases during metastable state due to changes in molecular size. | |
| 188. |
Which of the following is not responsible for phase deposition? |
| A. | container wall |
| B. | grain size |
| C. | stacking effect |
| D. | disjoints |
| Answer» A. container wall | |
| Explanation: under equilibrium conditions, the molecules adhere to the center of the | |
| 189. |
Where does the particle growth occur? |
| A. | movement of grains |
| B. | movement of equilibrium liquid |
| C. | equilibrium mixture |
| D. | non equilibrium mixture |
| Answer» A. movement of grains | |
| Explanation: during diffusion process in the transformation of solid to vapor state, the molecules move from regions of higher concentration to regions of lower concentrations and hence growth takes place n a controlled way. | |
| 190. |
Overall transformation rate changes with temperature as follows under what condition? |
| A. | decreases |
| B. | increases then decreases |
| C. | follows a linear path |
| D. | increases with temperature |
| Answer» B. increases then decreases | |
| Explanation: according to the phase graph, at the solidus region, the temperature is high. as the melting point increases, the temperature decreases and vice versa (applicable to all component systems). | |
| 191. |
Acetylene and synthesis gas are examples of |
| A. | primary gaseous fuels |
| B. | gaseous fuels |
| C. | secondary gaseous fuels |
| D. | liquid fuels |
| Answer» C. secondary gaseous fuels | |
| Explanation: since both acetylene and synthesis gas are formed by certain process and both are gaseous in nature, therefore they are secondary gaseous fuels. acetylene can be formed by the hydrolysis of calcium carbide. | |
| 192. |
Alcohol is a primary fuel. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: alcohol are formed by direct hydration of alkenes, that is why this is a false statement. formation of ethanol by the hydration of ethylene. | |
| 193. |
Which of the fuel does have highest specific energy? |
| A. | diesel |
| B. | coal |
| C. | kerosene |
| D. | nitromethane |
| Answer» A. diesel | |
| Explanation: specific energy is the amount of energy liberated after combustion, as among these diesel liberated the highest amount of energy which is 48 mj/kg. | |
| 194. |
Which type of coal give more amount of heat after combustion? |
| A. | anthracite |
| B. | peat |
| C. | lignite |
| D. | bituminous |
| Answer» A. anthracite | |
| Explanation: the coal is formed along this process | |
| 195. |
Which fuel is best suitable for blast furnace process? |
| A. | diesel |
| B. | hydrogen gas |
| C. | coal |
| D. | coke |
| Answer» D. coke | |
| Explanation: coke is best suitable for blast furnace process as it also acts as a reducing agent in smelting iron ore. the specific heat of coke is 0.85 kj/kg k. | |
| 196. |
Which fuel causes least pollution? |
| A. | diesel |
| B. | coal |
| C. | lpg (liquid petroleum gas) |
| D. | hydrogen gas |
| Answer» D. hydrogen gas | |
| Explanation: pollution is mainly caused by the presence of co2 in air. since after combustion of h2 it only gives water vapour which is less polluting. | |
| 197. |
Which of the gas is not a constituent of biogas? |
| A. | methane |
| B. | hydrogen |
| C. | co2 |
| D. | so2 (sulphur di-oxide) |
| Answer» D. so2 (sulphur di-oxide) | |
| Explanation: since biogas is formed by the domestic waste of home and industries, it does not contain the gases like so2, no2 etc. it does contain the hydrogen sulphide. | |
| 198. |
Which fuel can be produced from the carbohydrate content of algae? |
| A. | butanol |
| B. | hydrogen gas |
| C. | coal |
| D. | lpg (liquid petroleum gas) |
| Answer» A. butanol | |
| Explanation: the carbohydrate part of algae is fermented due to which butanol is produced. by this process, bio-ethanol can also be produced. | |
| 199. |
Which of the following fuel cannot be used in producing nuclear energy? |
| A. | plutonium |
| B. | uranium |
| C. | tritium |
| D. | deuterium |
| Answer» D. deuterium | |
| Explanation: since deuterium contains two electrons in its shell, it becomes difficult to break into a fully filled octet, due to which it cannot be used as a fuel in nuclear energy. | |
| 200. |
How does the texture of coal changes with its maturity? |
| A. | becomes hard, less brittle and moderately tough |
| B. | becomes hard, more brittle and more tough |
| C. | becomes hard, more brittle and less tough |
| D. | no change |
| Answer» B. becomes hard, more brittle and more tough | |
| Explanation: the texture of coal tends to the layer present on the coal and its maturity is from lignite to anthracite. the number of layers from lignite to anthracite increases due | |
Done Studing? Take A Test.
Great job completing your study session! Now it's time to put your knowledge to the test. Challenge yourself, see how much you've learned, and identify areas for improvement. Don’t worry, this is all part of the journey to mastery. Ready for the next step? Take a quiz to solidify what you've just studied.