MCQOPTIONS
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MCQOPTIONS
This section includes 4791 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 301. |
Thermal diffusivity is a |
| A. | function of temperature |
| B. | physical property of a substance |
| C. | dimensionless parameter |
| D. | all of these |
| Answer» C. dimensionless parameter | |
| 302. |
In aqua-ammonia and Lithium-bromide water absorption refrigeration systems, the refrigerants are respectively |
| A. | water and water |
| B. | water and lithium bromide |
| C. | ammonia and lithium bromide |
| D. | ammonia and water |
| Answer» E. | |
| 303. |
As relative humidity decreases, the dew point temperature will be __________ wet bulb temperature. |
| A. | same as |
| B. | lower than |
| C. | higher man |
| Answer» C. higher man | |
| 304. |
Reynolds number (RN) is given by (where h = Film coefficient, l = Linear dimension, V = Velocity of fluid, k = Thermal conductivity, t = Temperature, = Density of fluid, cp = Specific heat at constant pressure, and = Coefficient of absolute viscosity) |
| A. | <img src="/_files/images/mechanical-engineering/heat-transfer-refrigeration-and-air-conditioning/410-81-1.png"> |
| B. | <img src="/_files/images/mechanical-engineering/heat-transfer-refrigeration-and-air-conditioning/410-81-2.png"> |
| C. | <img src="/_files/images/mechanical-engineering/heat-transfer-refrigeration-and-air-conditioning/410-81-3.png"> |
| D. | <img src="/_files/images/mechanical-engineering/heat-transfer-refrigeration-and-air-conditioning/410-81-4.png"> |
| Answer» D. <img src="/_files/images/mechanical-engineering/heat-transfer-refrigeration-and-air-conditioning/410-81-4.png"> | |
| 305. |
The total radiation from a black body per second per unit area is __________ fourth power of the absolute temperature. This statement is known as Stefan-Boltzmann law. |
| A. | equal to |
| B. | directly proportional to |
| C. | inversely proportional to |
| Answer» C. inversely proportional to | |
| 306. |
The process of heat transfer from a hot body to a cold body, in a straight line, without affecting the intervening medium, is called radiation. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 307. |
In hot machining, tool is made of |
| A. | tungsten carbide |
| B. | brass or copper |
| C. | diamond |
| D. | stainless steel |
| Answer» B. brass or copper | |
| 308. |
In ultra-sonic machining, the metal is removed by |
| A. | using abrasive slurry between the tool and work |
| B. | direct contact of tool with the work |
| C. | maintaining an electrolyte between the work and tool in a very small gap between the two |
| D. | erosion caused by rapidly recurring spark discharges between the tool and work |
| Answer» B. direct contact of tool with the work | |
| 309. |
The machining of titanium is difficult due to |
| A. | high thermal conductivity of titanium |
| B. | chemical reaction between tool and work |
| C. | low tool-chip contact area |
| D. | none of these |
| Answer» D. none of these | |
| 310. |
Lapping is an operation of |
| A. | making a cone-shaped enlargement of the end of a hole |
| B. | smoothing and squaring the surface around a hole |
| C. | sizing and finishing a small diameter hole |
| D. | producing a hole by removing metal along the circumference of a hollow cutting tool |
| Answer» D. producing a hole by removing metal along the circumference of a hollow cutting tool | |
| 311. |
In orthogonal cutting system, the maximum chip thickness occurs at the middle. |
| A. | Correct |
| B. | Incorrect |
| Answer» B. Incorrect | |
| 312. |
Grinding wheels should be tested for balance |
| A. | only at the time of manufacture |
| B. | before starting the grinding operation |
| C. | at the end of grinding operation |
| D. | occasionally |
| Answer» E. | |
| 313. |
The velocity of tool relative to the workpiece is known as cutting velocity. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 314. |
Which of the following statement is wrong about ultra-sonic machining? |
| A. | It is best suited for machining hard and brittle materials. |
| B. | It cuts materials at very slow speeds. |
| C. | It removes large amount of material. |
| D. | It produces good surface finish. |
| Answer» D. It produces good surface finish. | |
| 315. |
The different spindle speeds on a lathe form |
| A. | arithmetical progression |
| B. | geometrical progression |
| C. | harmonical progression |
| D. | any one of these |
| Answer» C. harmonical progression | |
| 316. |
A drill considered as a cutting tool having zero rake, is known as a |
| A. | flat drill |
| B. | straight fluted drill |
| C. | parallel shank twist drill |
| D. | tapered shank twist drill |
| Answer» C. parallel shank twist drill | |
| 317. |
In oblique cutting system, the maximum chip thickness occurs at the middle. |
| A. | Correct |
| B. | Incorrect |
| Answer» C. | |
| 318. |
If the helix angle of the drill is made __________ 30 , then the torque required to drive the drill at a given feed will be more. |
| A. | equal to |
| B. | less than |
| C. | more than |
| Answer» C. more than | |
| 319. |
Larger end cutting edge angle __________ tool life. |
| A. | increases |
| B. | decreases |
| C. | does not effect |
| Answer» C. does not effect | |
| 320. |
The lead screw of a lathe has __________ threads. |
| A. | single start |
| B. | double start |
| C. | multi-start |
| D. | any one of these |
| Answer» B. double start | |
| 321. |
Gear lapping is an operation |
| A. | after heat treatment |
| B. | prior to heat treatment |
| C. | for gear reconditioning |
| D. | none of these |
| Answer» B. prior to heat treatment | |
| 322. |
The facing is an operation of |
| A. | bevelling the extreme end of a workpiece |
| B. | embossing a diamond shaped pattern on the surface of a workpiece |
| C. | reducing the diameter of a workpiece over a very narrow surface |
| D. | machining the ends of a workpiece to produce a flat surface square with the axis |
| Answer» E. | |
| 323. |
A fixture is defined as a device which |
| A. | holds and locates a workpiece and guides and controls one or more cutting tools |
| B. | holds and locates a workpiece during an inspection or for a manufacturing operation |
| C. | is used to check the accuracy of workpiece |
| D. | all of the above |
| Answer» C. is used to check the accuracy of workpiece | |
| 324. |
The lip angle of a single point tool is usually |
| A. | 20 to 40 |
| B. | 40 to 60 |
| C. | 60 to 80 |
| D. | none of these |
| Answer» D. none of these | |
| 325. |
The average cutting speed for turning brass with a high speed steel tool is |
| A. | 15 to 19 m/min |
| B. | 25 to 31 m/min |
| C. | 60 to 90 m/min |
| D. | 90 to 120 m/min |
| Answer» D. 90 to 120 m/min | |
| 326. |
The maximum production of small and slender parts is done by |
| A. | watch maker's lathe |
| B. | sliding head stock automatic lathe |
| C. | multispindle automatic lathe |
| D. | capastan lathe |
| Answer» D. capastan lathe | |
| 327. |
Side rake angle on tools is provided to control chip flow. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 328. |
A left hand tool on a lathe cuts most efficiently when it travels |
| A. | from left to right end of the lathe bed |
| B. | from right to left end of the lathe bed |
| C. | with the help of a compound slide |
| D. | across the bed |
| Answer» B. from right to left end of the lathe bed | |
| 329. |
The method of grinding used to produce a straight or tapered surface on a workpiece, is |
| A. | internal cylindrical grinding |
| B. | form grinding |
| C. | external cylindrical grinding |
| D. | surface grinding |
| Answer» D. surface grinding | |
| 330. |
Which of the following statement is incorrect with reference of lathe cutting tools? |
| A. | The flank of the tool is the surface or surfaces below and adjacent to the cutting edges |
| B. | The nose is the corner, arc or chamfer joining the side cutting and the end cutting edges |
| C. | The heel is that part of the tool which is shaped to produce the cutting edges and face |
| D. | The base is that surface of the shank which bears against the support and takes tangent pressure of the cut |
| Answer» D. The base is that surface of the shank which bears against the support and takes tangent pressure of the cut | |
| 331. |
In the relation VTn = C, the value of n for carbide tools is |
| A. | 0.1 to 0.2 |
| B. | 0.20 to 0.25 |
| C. | 0.25 to 0.40 |
| D. | 0.40 to 0.55 |
| Answer» C. 0.25 to 0.40 | |
| 332. |
In up milling, the thickness of chip is |
| A. | minimum at the beginning of the cut and maximum at the end of the cut |
| B. | maximum at the beginning of the cut and minimum at the end of the cut |
| C. | uniform throughout the cut |
| D. | none of these |
| Answer» B. maximum at the beginning of the cut and minimum at the end of the cut | |
| 333. |
The optimum effective temperature for human comfort is |
| A. | higher in winter than in summer |
| B. | lower in winter than in summer |
| C. | same in winter and summer |
| D. | not dependent on season |
| Answer» C. same in winter and summer | |
| 334. |
The correct sequence of tool materials in increasing order of their ability to retain their hot hardness is |
| A. | carbide, ceramic, cermet, borazon |
| B. | ceramic, carbide, borazon, cermet |
| C. | cermet, carbide, ceramic, borazon |
| D. | borazon, ceramic, carbide, cermet |
| Answer» D. borazon, ceramic, carbide, cermet | |
| 335. |
A fixture does not guide the tool. |
| A. | Correct |
| B. | Incorrect |
| Answer» B. Incorrect | |
| 336. |
The by-pass factor for a cooling coil |
| A. | increases with increase in velocity of air passing through it |
| B. | decreases with increase in velocity of air passing through it |
| C. | remains unchanged with increase in velocity of air passing through it |
| D. | may increase or decrease with increase in velocity of air passing through it depending upon the condition of air entering |
| Answer» B. decreases with increase in velocity of air passing through it | |
| 337. |
The difference between dry bulb temperature and wet bulb temperature, is called |
| A. | dry bulb depression |
| B. | wet bulb depression |
| C. | dew point depression |
| D. | degree of saturation |
| Answer» C. dew point depression | |
| 338. |
Fourier's law of heat conduction is (where Q = Amount of heat flow through the body in unit time, A = Surface area of heat flow, taken at right angles to the direction of heat flow, dT = Temperature difference on the two faces of the body, dx = Thickness of the body, through which the heat flows, taken along the direction of heat flow, and k = Thermal conductivity of the body) |
| A. | <img src="/_files/images/mechanical-engineering/heat-transfer-refrigeration-and-air-conditioning/404-14-1.png"> |
| B. | <img src="/_files/images/mechanical-engineering/heat-transfer-refrigeration-and-air-conditioning/404-14-2.png"> |
| C. | <img src="/_files/images/mechanical-engineering/heat-transfer-refrigeration-and-air-conditioning/404-14-3.png"> |
| D. | <img src="/_files/images/mechanical-engineering/heat-transfer-refrigeration-and-air-conditioning/404-14-4.png"> |
| Answer» B. <img src="/_files/images/mechanical-engineering/heat-transfer-refrigeration-and-air-conditioning/404-14-2.png"> | |
| 339. |
Defrosting of a refrigerator may be done by stopping the compressor for a short period. |
| A. | Correct |
| B. | Incorrect |
| Answer» B. Incorrect | |
| 340. |
The heat transfer by conduction through a thick sphere is same as through a thick cylinder. |
| A. | True |
| B. | False |
| Answer» C. | |
| 341. |
The heat transfer by conduction through a thick sphere is given by |
| A. | <img src="/_files/images/mechanical-engineering/heat-transfer-refrigeration-and-air-conditioning/405-33-1.png"> |
| B. | <img src="/_files/images/mechanical-engineering/heat-transfer-refrigeration-and-air-conditioning/405-33-2.png"> |
| C. | <img src="/_files/images/mechanical-engineering/heat-transfer-refrigeration-and-air-conditioning/405-33-3.png"> |
| D. | <img src="/_files/images/mechanical-engineering/heat-transfer-refrigeration-and-air-conditioning/405-33-4.png"> |
| Answer» C. <img src="/_files/images/mechanical-engineering/heat-transfer-refrigeration-and-air-conditioning/405-33-3.png"> | |
| 342. |
The efficiency of a jet engine is higher at |
| A. | low speeds |
| B. | high speeds |
| C. | low altitudes |
| D. | high altitudes |
| Answer» E. | |
| 343. |
A perfect black body is one which |
| A. | is black in colour |
| B. | absorbs heat radiations of all wave lengths falling on it |
| C. | reflects all the heat radiations |
| D. | transmits the heat radiations |
| Answer» C. reflects all the heat radiations | |
| 344. |
The coefficient of performance of Heat Pump is always __________ one. |
| A. | equal to |
| B. | less than |
| C. | greater than |
| Answer» D. | |
| 345. |
The volume of air delivered by the compressor is called |
| A. | free air delivery |
| B. | compressor capacity |
| C. | swept volume |
| D. | none of these |
| Answer» C. swept volume | |
| 346. |
The maximum delivery pressure in a rotary air compressor is |
| A. | 10 bar |
| B. | 20 bar |
| C. | 30 bar |
| D. | 50 bar |
| Answer» B. 20 bar | |
| 347. |
During adiabatic saturation process on unsaturated air __________ remains constant. |
| A. | relative humidity |
| B. | dew point temperature |
| C. | dry bulb temperature |
| D. | wet bulb temperature |
| Answer» E. | |
| 348. |
The rotary compressors are suitable for large discharge of air at low pressure. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 349. |
The stagnation pressure rise in a centrifugal compressor takes place |
| A. | in the diffuser only |
| B. | in the impeller only |
| C. | in the diffuser and impeller |
| D. | in the inlet guide vanes only |
| Answer» D. in the inlet guide vanes only | |
| 350. |
An open cycle gas turbine works on the same cycle as that of a closed cycle gas turbine. |
| A. | Yes |
| B. | No |
| Answer» B. No | |