McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Uncategorized topics .
| 301. |
For an aluminium the modulus of rigidity is 2.1×1010 N/m2 and density is 2.7×103 kg/m3. Find the speed of transverse waves in the medium. |
| A. | 27.9×103 m/s |
| B. | 2.79×103 m/s |
| C. | 25.14×103 m/s |
| D. | 24.1×103 m/s |
| Answer» B. 2.79×103 m/s | |
| Explanation: speed = √(Ƞ/ƿ) speed = 2.79×103 m/s. | |
| 302. |
Sound travels through a gas under which of the following condition? |
| A. | isothermal condition |
| B. | non-isothermal condition |
| C. | adiabatic condition |
| D. | transverse condition |
| Answer» C. adiabatic condition | |
| Explanation: the compressions and rarefactions are formed so rapidly that the heat generated in the regions of compressions does not get time to pass into the regions of rarefactions so as to equalize the temperature. so when sound travels through gas, the temperature remains constant. therefore, it is adiabatic. | |
| 303. |
What kind of wave is formed in organ pipes? |
| A. | transverse stationary waves |
| B. | electromagnetic waves |
| C. | mechanical waves |
| D. | longitudinal stationary waves |
| Answer» D. longitudinal stationary waves | |
| Explanation: when two identical longitudinal waves travelling in opposite directions overlap, a longitudinal stationary wave is formed. thus, the waves produced in organ pipes are longitudinal stationary waves. | |
| 304. |
A wave transmits momentum. Can’t it transfer angular momentum? |
| A. | yes |
| B. | no |
| Answer» B. no | |
| Explanation: a wave transmitting momentum cannot transmit angular momentum because a transfer of angular momentum means the action of a torque which causes rotator motion. | |
| 305. |
What is the most fundamental property of wave? |
| A. | temperature |
| B. | pressure |
| C. | frequency |
| D. | wavelength |
| Answer» C. frequency | |
| Explanation: when a wave travels from one medium to other, its wavelength as well as velocity may change. this is the reason that frequency is the fundamental property of a wave. | |
| 306. |
Which of the following is also known as pressure waves? |
| A. | transverse waves |
| B. | longitudinal waves |
| C. | mechanical waves |
| D. | stationary waves |
| Answer» B. longitudinal waves | |
| Explanation: longitudinal waves travel in a medium as series of alternate compressions and rarefactions and hence are called pressure waves. | |
| 307. |
In which medium sound travels faster? |
| A. | solid |
| B. | liquid |
| C. | gas |
| D. | water vapour |
| Answer» A. solid | |
| Explanation: sound travels in solid with the highest speed because the coefficient of elasticity of solids is much greater than the coefficient of elasticity of liquids and gases. | |
| 308. |
TEM and SEM are the same microscopy techniques. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: transmission electron microscopy (tem) and scanning electron microscopy (sem) are the different types of | |
| 309. |
The resolving power of TEM is derived from |
| A. | electrons |
| B. | specimens |
| C. | power |
| D. | ocular system |
| Answer» A. electrons | |
| Explanation: the resolving power of a transmission electron microscope is derived from the wave-like property of electrons that pass through the specimen. in sem, the electrons reflect back from the specimen. | |
| 310. |
The cathode of transmission electron microscope consists of a |
| A. | tungsten wire |
| B. | bulb |
| C. | iron filament |
| D. | gold wire |
| Answer» A. tungsten wire | |
| Explanation: the cathode of a transmission electron microscope (tem) is located on top of the column, it contains a tungsten wire filament that is heated to provide the source of electrons. | |
| 311. |
The resolution attainable with standard TEM is less than the theoretical value. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: the resolution that can be attained with a standard transmission electron microscope is about two orders of magnitude less than the theoretical value. this is due to spherical aberration of electron-focusing lenses. | |
| 312. |
During TEM, a vacuum is created inside the |
| A. | room of operation |
| B. | specimen |
| C. | column |
| D. | ocular system |
| Answer» C. column | |
| Explanation: to prevent the premature scattering of electrons by collision with the gas molecules, a vacuum is generated through which the electrons travel, in the column prior to operation. | |
| 313. |
Which of the following component of TEM focuses the beam of electrons on the sample? |
| A. | ocular lens |
| B. | condenser lens |
| C. | stage |
| D. | column |
| Answer» B. condenser lens | |
| Explanation: the condenser lens focuses the electron beam on to the specimen, in case of transmission electron microscope. the specimen is supported on the grid holder and placed inside the column. | |
| 314. |
Image formation in electron microscope is based on |
| A. | column length |
| B. | electron number |
| C. | differential scattering |
| D. | specimen size |
| Answer» C. differential scattering | |
| Explanation: in case of the electron microscope, the image formation is based on the differential scattering of the electrons by parts of the specimen. the scattering of electrons is proportional to the size nuclei of the atoms that make up the sample. | |
| 315. |
The biological materials have little intrinsic capability to |
| A. | scatter electrons |
| B. | stain |
| C. | remain viable |
| D. | be captured |
| Answer» A. scatter electrons | |
| Explanation: the insoluble materials of cells contain atoms of low atomic number such as carbon, hydrogen, oxygen and nitrogen. the biological materials therefore have very little intrinsic capability of scattering the electrons. | |
| 316. |
Glutaraldehyde is a |
| A. | metal |
| B. | fixative |
| C. | non-metal |
| D. | atomic species |
| Answer» B. fixative | |
| Explanation: glutaraldehyde and osmium tetroxide are common fixatives used in the transmission electron microscopy for the fixation of biological specimens. they stain as well as keep the sectioned specimens in a state of similarity with the living counterpart. | |
| 317. |
Osmium is a |
| A. | non metal |
| B. | heavy metal |
| C. | alloy |
| D. | light metal |
| Answer» B. heavy metal | |
| Explanation: osmium is a heavy metal that reacts with fatty acids leading to the preservation of membranes. osmium tetroxide is used as a fixative in transmission | |
| 318. |
Shadow casting is a technique of visualizing |
| A. | isolated particles |
| B. | mounts |
| C. | shoot tips |
| D. | root tips |
| Answer» A. isolated particles | |
| Explanation: shadow casting is a technique of viewing isolated particles. the particles are made to cast shadows after their placement in sealed chambers. the chamber contains a filament of carbon and a heavy metal. | |
| 319. |
Which of the following can be a wave function? |
| A. | tan x |
| B. | sin x |
| C. | cot x |
| D. | sec x |
| Answer» B. sin x | |
| Explanation: out of all the given options, sin x is the only function, that is continuous and single-valued. all the rest of the functions are either discontinuous or double-valued. | |
| 320. |
Which of the following is not a characteristic of wave function? |
| A. | continuous |
| B. | single valued |
| C. | differentiable |
| D. | physically significant |
| Answer» D. physically significant | |
| Explanation: the wave function has no physical significance. it merely helps in determining the state of a particle. it is the square of the wave function that has a physical significance. | |
| 321. |
dΨ/dx must be zero. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: for a wave function, dΨ/dx, must be continuous and single-valued everywhere, just like Ψ. also, Ψ must be normalizable. | |
| 322. |
Any wave function can be written as a linear combination of |
| A. | eigen vectors |
| B. | eigen values |
| C. | eigen functions |
| D. | operators |
| Answer» C. eigen functions | |
| Explanation: a wave function describes the state of a particle. it does not have a physical significance. moreover, it can be written as a linear combination of eigen functions, i.e., Ψ(x) = af(x) + bg(x). | |
| 323. |
The Schrödinger is a differential equation. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: the schrodinger wave equation | |
| 324. |
The walls of a particle in a box are supposed to be |
| A. | small but infinitely hard |
| B. | infinitely large but soft |
| C. | soft and small |
| D. | infinitely hard and infinitely large |
| Answer» D. infinitely hard and infinitely large | |
| Explanation: the simplest quantum- mechanical problem is that of a particle in a box with infinitely hard walls and are infinitely large. | |
| 325. |
The wave function of the particle lies in which region? |
| A. | x > 0 |
| B. | x < 0 |
| C. | 0 < x < l |
| D. | x > l |
| Answer» C. 0 < x < l | |
| Explanation: the particle cannot exist outside the box, as it cannot have infinite amount of energy. thus, it’s wave function is between 0 and l, where l is the length of the side of the box. | |
| 326. |
The particle loses energy when it collides with the wall. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: the total energy of the particle inside the box remains constant. it does not loses energy when it collides with the wall. | |
| 327. |
The Energy of the particle is proportional to |
| A. | n |
| B. | n-1 |
| C. | n2 |
| D. | n-2 |
| Answer» C. n2 | |
| Explanation: in a particle inside a box, the energy of the particle is directly proportional to the square of the quantum state in which the particle currently is. | |
| 328. |
For a particle inside a box, the potential is maximum at x = |
| A. | l |
| B. | 2l |
| C. | l/2 |
| D. | 3l |
| Answer» A. l | |
| Explanation: in a box with infinitely high barriers with infinitely hard walls, the potential is infinite when x = 0 and when x = l. | |
| 329. |
The Eigen value of a particle in a box is |
| A. | l/2 |
| B. | 2/l |
| C. | √l/2 |
| D. | √2/l |
| Answer» D. √2/l | |
| Explanation: the wave function for the particle in a box is normalizable, when the value of the coefficient of sin is equal to | |
| 330. |
Particle in a box can never be at rest. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: if the particle in a box has zero energy, it will be at rest inside the well and it violates the heisenberg’s uncertainty principle. thus, the minimum energy possessed by a particle is not equal to zero. | |
| 331. |
The wave function for which quantum state is shown in the figure? |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» B. 2 | |
| Explanation: the shown wave function is for the 2nd principal quantum number, i.e., it is the wave function for the state when n = 2. | |
| 332. |
The line at which the tunnel wall breaks from sloping outward can be given as |
| A. | spring line |
| B. | oval line |
| C. | centre line |
| D. | middle line |
| Answer» A. spring line | |
| Explanation: spring line is determined as the line at which the wall breaks from sloping outward to sloping inward toward the crown. | |
| 333. |
Which of the following should be considered while aligning a tunnel? |
| A. | atmospheric conditions |
| B. | hydrological conditions |
| C. | climatic conditions |
| D. | surface limits |
| Answer» B. hydrological conditions | |
| Explanation: the determination of the alignment for tunnel can be done based on geological and hydrological conditions, cross- section and length of the continuous tunnel, time of consideration and limit of the surface. | |
| 334. |
Among the following, which doesn’t belong to tunnel classification? |
| A. | firm ground |
| B. | running ground |
| C. | rocky ground |
| D. | soft ground |
| Answer» C. rocky ground | |
| Explanation: tunneling has been classified based on the type of strata present. it includes firm ground, soft ground and running ground. these will determine the bearing capacity of the soil. | |
| 335. |
Which method can be adopted if full face excavation is not possible? |
| A. | back bearing method |
| B. | plotting |
| C. | trenching |
| D. | benching |
| Answer» D. benching | |
| Explanation: in case of no possibility of full face excavation, top heading method is adopted for having a better output. benching process is also adopted for digging small tunnels. | |
| 336. |
Among the following, which can be adopted for providing support for soft strata? |
| A. | bents of aluminum |
| B. | bents of iridium |
| C. | bents of steel |
| D. | bents of plastic |
| Answer» C. bents of steel | |
| Explanation: the provision of soft strata must be done for withstanding the excavation. it can be provided by bents of wood, bents of steel, liner plates and poling, which are placed to retain material between the adjacent bents. | |
| 337. |
A steel cylinder which is pushed in the soft soil is determined as |
| A. | jar born |
| B. | shield |
| C. | rod |
| D. | pole |
| Answer» B. shield | |
| Explanation: in the case of soft grounds, tunneling can be dangerous and cave-ins are common. to prevent this, an iron or steel cylindrical element called shield is placed in the soft soil, which can crave the hole perfectly. | |
| 338. |
Which method can be adopted in case of rock tunneling? |
| A. | full face method |
| B. | benching |
| C. | tracing |
| D. | back bearing method |
| Answer» A. full face method | |
| Explanation: rock tunneling involves the same principle as of the tunneling in the ground. those include full face method, top heading method and drift method. based on the conditions of the area, these can be adopted. | |
| 339. |
Which of the following can act as an alternative for blasting? |
| A. | tunneling |
| B. | continuous blasting |
| C. | sequential blasting |
| D. | fire-setting |
| Answer» D. fire-setting | |
| Explanation: blasting is the conventional method which is adopted in case of rock tunneling. in the case of fire-setting, tunnel is heated with fire and then cooled with water. rapid expansion and contraction weakens and rock and tends to break. | |
| 340. |
Which of the following involves in the sequence of rocky strata? |
| A. | marking profile |
| B. | placing rocks |
| C. | improving foul gases |
| D. | recording values |
| Answer» A. marking profile | |
| Explanation: rocky strata involve usage of blasting method for developing tunnels. the sequence contains marking profile, loading explosive, removing foul gases, checking, scaling, mucking and bolting. | |
| 341. |
Which of the following are true for electron microscopy? |
| A. | specimen should be thin and dry |
| B. | image is obtained on a phosphorescent screen |
| C. | electron beam must pass through evacuated chamber |
| D. | specimen should be thin and dry, image is obtained on a phosphorescent screen and electron beam must pass through evacuated chamber |
| Answer» D. specimen should be thin and dry, image is obtained on a phosphorescent screen and electron beam must pass through evacuated chamber | |
| Explanation: since electrons can travel only in high vacuum, the entire electron path through the instrument must be evacuated; specimens must be completely dehydrated prior to examination. only very thin specimens can be observed in the conventional electron microscope since the penetrating power of electrons through matter is weak. the magnified image may be viewed on a phosphorescent or fluorescent screen. | |
| 342. |
Negative Staining is used for examining |
| A. | virus particles |
| B. | protein molecules |
| C. | bacterial flagella |
| D. | virus particles, protein molecules and bacterial flagella |
| Answer» D. virus particles, protein molecules and bacterial flagella | |
| Explanation: in negative-staining the electron opacity of the surrounding field is increased by using an electron-dense material such as phosphotungstic acid as a stain. | |
| 343. |
Which among the following helps us in getting a three-dimensional picture of the specimen? |
| A. | transmission electron microscope |
| B. | scanning electron microscope |
| C. | compound microscope |
| D. | simple microscope |
| Answer» B. scanning electron microscope | |
| Explanation: the scanning electron microscope lacks the resolving power obtainable with the transmission electron microscope but has the advantage of revealing a striking three-dimensional picture. the surface topography of a specimen can be revealed with clarity and depth of field not possible by any other method. | |
| 344. |
The secondary electrons radiated back in scanning microscope is collected by? |
| A. | specimen |
| B. | anode |
| C. | vacuum chamber |
| D. | cathode |
| Answer» B. anode | |
| Explanation: in scanning electron | |
| 345. |
On what factors do the intensity of secondary electrons depend upon? |
| A. | shape of the irradiated object |
| B. | chemical composition of the irradiated object |
| C. | number of electrons ejected |
| D. | size and chemical composition of the irradiated object, number of electrons ejected and on the number of electrons reabsorbed by surrounding |
| Answer» D. size and chemical composition of the irradiated object, number of electrons ejected and on the number of electrons reabsorbed by surrounding | |
| Explanation: the irradiations in sem causes secondary electrons to be ejected from the specimen thereby generating a signal that is proportional to the number of electrons striking the anode. the intensity or the number of secondary electrons depends on the shape and the chemical composition of the irradiated object and also on the number of electrons ejected and the number of electrons reabsorbed by surrounding. | |
| 346. |
Where do we obtain the magnified image of the specimen in SEM? |
| A. | cathode ray tube |
| B. | phosphorescent screen |
| C. | anode |
| D. | scanning generator |
| Answer» A. cathode ray tube | |
| Explanation: in tem, the image is obtained on a phosphorescent screen but in sem the magnified image of the surface topography of the specimen is obtained on the cathode ray tube. the electronic signals generated scan the specimen in a raster pattern in the manner of a television system to produce an image on a cathode ray tube. | |
| 347. |
Which of the following techniques are used in Transmission Electron Microscopy (TEM) for examining cellular structure? |
| A. | negative-staining |
| B. | shadow casting |
| C. | ultrathin sectioning |
| D. | negative-staining, shadow casting, ultrathin sectioning, freeze-etching |
| Answer» D. negative-staining, shadow casting, ultrathin sectioning, freeze-etching | |
| Explanation: numerous techniques are available for use with electron microscopy which extends its usefulness in characterizing cellular structure. some of them are | |
| 348. |
Which of the following properties is generally exhibited by amorphous solids? |
| A. | anisotropy |
| B. | glass-transition |
| C. | equal strength of all bonds |
| D. | all of the mentioned |
| Answer» B. glass-transition | |
| Explanation: due to random organization of particles, amorphous solids have the same physical properties along all directions, or are isotropic. random organization of particles also results in unequal bond strengths. upon cooling, amorphous solids turn into a brittle | |
| 349. |
Metal glass was first prepared at: |
| A. | california institute of technology |
| B. | massachusetts institute of technology |
| C. | technion |
| D. | university of michigan |
| Answer» A. california institute of technology | |
| Explanation: metal glass or amorphous metal was reportedly first produced by w. klement (jr.), willens and duwez in 1960 at caltech. it was prepared by rapid cooling (~ 1 mk/s) of molten metal alloys. | |
| 350. |
Polycrystalline solids are isotropic. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: anisotropy is a characteristic behavior shown by ideal crystals. however, | |
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