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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 451. |
If two light nuclei are fused together in nuclear reaction, the average energy per nucleonA. IncreasesB. DecreasesC. Cannot be determinedD. Remains same |
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Answer» Correct Answer - B Due to mass defect some energy is lost as heat energy. |
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| 452. |
If two light nuclei are fused together in nuclear reaction the average energy per nucleonA. IncreasesB. Cannot be determinedC. Remains sameD. Decrease |
| Answer» Correct Answer - D | |
| 453. |
The radial distribution curve of ` 2s` sub-level consists of `x` nodes. Value of `x` is : |
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Answer» Correct Answer - 1 `n=4` `l=0, 1, 2, 3` `s, p, d, f` So, number of orbitals `=s=1, p=3, d=5, f=7` Number of elements `=1xx3+3xx3+5xx3+7xx3=48` |
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| 454. |
Mass number and atomic number of an atom are 232 and 90 respectively. How many `alpha-` particles of this atom must emit, after the emission of `2 beta-`particles, such that the mass number and atomic number of new element are 212 and 82 respectively |
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Answer» Correct Answer - 5 `._(9)^(232)A overset(-2 beta)rarr ._(90)^(232)B rarr ._(82)^(212)C + m_(2)^(4) He` In above nuclear reaction, `232 = 212 + m xx 4` or `m = (232 - 212)/(4) = 5 alpha`- particles |
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| 455. |
India conducted an underground nuclear test atA. TarapurB. NaroraC. PokhranD. Pushkar |
| Answer» Correct Answer - C | |
| 456. |
An electron is continuonsly accelerated in vacume tube by appliying potential difference if its de Brogle wavelength is decresed by `1%` the change in the kinetic energy of the electron is nearlyA. Decreased by `1%`B. Increased by `2%`C. Increased by `1%`D. Decreased by `2%` |
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Answer» Correct Answer - B `(hc)/(lambda)=E_(1)-E_(2)=KE_(2)-KE_(1)` `:. Lambda=h/(mV) (mV)^(2)=(h/lambda)^(2), 1/2 mV^(2)=1/(2m)h^(2)/lambda^(2)` `:. (hc)/lambda=h^(2)/(2m lambda_(2)^(2))-h^(2)/(2mlambda_(1)^(2)) :. Lambda=(2mc)/(h){(lambda_(1)^(2)lambda_(2)^(2))/(lambda_(1)^(2)-lambda_(2)^(2))}` |
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| 457. |
The half life of `Ra` is 1600 years. The fraction of a sample of `Ra` that would remain after 6400 years isA. `(1)/(4)`B. `(1)/(2)`C. `(1)/(8)`D. `(1)/(16)` |
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Answer» Correct Answer - D `t_(1//2)=1600 years, T=6400 years` `:. n=(T)/(t_(1//2))=(6400)/(1600)=4` `N=((1)/(2))^(n)N_(0)` `=(N)/(N_(0))=((1)/(2))^(4)=(1)/(16)` |
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| 458. |
Which of the following cannot be acceleratedA. `alpha-`particleB. `beta-`particleC. ProtonsD. Neutron |
| Answer» Correct Answer - A | |
| 459. |
Which of the following sub-atomic particles is not present in an atomA. NeutronB. ProtonC. ElectronD. Positron |
| Answer» Correct Answer - D | |
| 460. |
Match the list I and list II and pick the correct matching from the codes given below A. `A -2, B-1, C-4, D -5, E -3`B. `A-2, B-5, C-1, D-4, E-3`C. `A-3, B-1, C-2, D-5, E-4`D. `A -5, B-4, C-1, D-2, E -3` |
| Answer» Correct Answer - C | |
| 461. |
The half life of `Ra` is 1600 years. The fraction of a sample of `Ra` that would remain after 6400 years isA. `1//16`B. `1//4`C. `1//8`D. `1//2` |
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Answer» Correct Answer - A `t_(1//2) = 1600` min, `T = 6400` min Number of half lives `= (6400)/(1600) = 4` We know that `N = ((1)/(2))^(n) N_(0)` or `(N)/(N_(0)) = ((1)/(2))^(n) = ((1)/(2))^(4) = (1)/(16)` |
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| 462. |
Match List I and List II and choose right one by using code given in list A. `{:(1,2,3,4),(B,A,C,E):}`B. `{:(1,2,3,4),(B,C,A,E):}`C. `{:(1,2,3,4),(C,B,A,E):}`D. `{:(1,2,3,4),(C,D,A,B):}` |
| Answer» Correct Answer - B | |
| 463. |
Atom with the same atomic number and different mass numbers are calledA. IsobarsB. IsomersC. IsotonesD. Isotopes |
| Answer» Correct Answer - D | |
| 464. |
Isotopes were discovered byA. AstonB. SoddyC. ThomsonD. Mullikan |
| Answer» Correct Answer - B | |
| 465. |
A counter rate metre is used to measure the activity of a radioactive sample. At a certain instant, the count rate was recorded as 400 counters per minute. Five minutes later, the count recorded was 200 counts per min. Calculate the decay and half-period of the sample. |
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Answer» Let `N_(0)` and `N` be the number rate atoms of the radioactive substance present at the start and after 5 min, respectively. Rate of disintegration at the start `= KN_(0) = 400` Dividing both, `(KN_(0))/(KN) = (400)/(200)` or `(N_(0))/(N) = 2.00` We know that `K = (2.303)/(t) log (N_(0))/(N)` ` K = (2.303)/(5) log 2.00 = 0.138 "min"^(-1)` Half life period `= (0.693)/(K) = (0.693)/(0.138) = 5.0` min |
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| 466. |
Half-life period for radioactive element isA. Always constantB. VariableC. Independent of final concentrationnD. Independent of initial concentration |
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Answer» Correct Answer - A::D `t_(1//2) = (0.693)/(K)` Therefore, `t_(1//2)` is always constant and independent of initial concentration. |
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| 467. |
Which of the following nuclides belong to actinium `(U^(235))` series?A. `Pb^(207)`B. `Po^(215)`C. `Po^(213)`D. `._(1)H^(3)` |
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Answer» Correct Answer - A::B Both `Pb^(207)` and `Po^(215)` belong to `4n + 3` series. |
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| 468. |
The correct starting material and product of different disintegration series `"is"//"are"`A. `Th^(232), Pb^(208)`B. `Np^(237),Bi^(209)`C. `U^(235),Pb^(206)`D. `U^(238),Pb^(206)` |
| Answer» Correct Answer - A::D | |
| 469. |
The half-life period of radon is 3.8 days. After how many will only one-twentieth of radon sample be left over? |
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Answer» We know that `K = (0.693)/(t_(1//2)) = (0.693)/(3.8) = 0.182 day^(-1)` Let the initial amountd of radon be `N_(0)` and the amount left after `t` days be `N`d which is equal to `N_(0)//10`. Applying the equation, `t = (2.303)/(K) log (N_(0))/(N)` `t = (2.303)/(0.182) log (N_(0))/(N_(0)//10)` `= (2.303)/(0.182) log 10 = 12.65` days Alternatively, `(t_(1//2))/(t_(x%)) = (0.3)/(log(a)/(a - x))` `implies (3.8)/(t_(x%)) = (0.3)/(log((a)/((1)/(10))a)` or `(3.8)/(t_(x%)) = (0.3)/(log 10)` `:. t_(x%) = (3.80)/(0.3) = 12.65` days |
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| 470. |
The isobars are atoms with the same number ofA. ProtonsB. NeutronsC. Protons and neutronsD. Nucleons |
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Answer» Correct Answer - DThe correct option is D Answer is : (D) Nucleons = Number of protons + Number of neutrons. Isobars have same mass number (Number of protons + Number of neutrons) but different atomic number (Number of protons). |
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| 471. |
Which of the following process not lead to formation of isobars?A. `1 alpha` particle and `2 beta` particles are emittedB. Positron emissionC. `beta` particle `(`_(-1)e^(0))`` emissionD. K-electron capture |
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Answer» Correct Answer - 1 `_(X)A^(Z) rarr_(X-2)B^(Z-4)+`_(2)He^(4)`` `_(X-2)B^(Z-4) rarr `_(X-1)C^(Z-4)+ `_(-1)e^(0)``` `_(X-1)C^(Z-4) rarr `_(X)D^(z-4)+ `_(-1)e^(0)``` |
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| 472. |
Which of the following pairs represents isobars?A. `._(19)K^(40)` and `._(11)Na^(23)`B. `._(2)He^(3)` and `._(2)He^(4)`C. `._(12)Mg^(24)` and `._(12)Mg^(25)`D. `._(19)K^(40)` and `._(20)Ca^(40)` |
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Answer» Correct Answer - D Isobars have same atomic mass number. |
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| 473. |
The reaction `._(5)B^(8) rarr ._(4)Be^(8) + ._(1)e^(0)` is due toA. Loss of `alpha`-particlesB. Loss of `beta-`particlesC. Loss of positronD. Electron loss |
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Answer» Correct Answer - C The emission of positron takes places |
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| 474. |
Which among the following nuclides `"is"//"are"` likely to be stable?A. `._(49)In^(114)`B. `._(12)Mg^(24)`C. `._(48)Cd^(114)`D. `._(15)P^(30)` |
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Answer» Correct Answer - B::C Both have even number of neutrons and protons and `n//p` ratio of `Mg = 1` and `Cd ~~ 1`. |
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| 475. |
Which of the following is not a fissionalbe material?A. `U^(238)`B. `U^(233)`C. `Pu^(239)`D. `U^(235)` |
| Answer» Correct Answer - A | |
| 476. |
Radon, actinon, and thoron are isobars. |
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Answer» Correct Answer - F |
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| 477. |
The element californium belongs to the family ofA. Actinide seriesB. Alkali metal familyC. Alkaline earth familyD. Lantnanide series |
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Answer» Correct Answer - A `Cf-98` belongs to actinite series |
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| 478. |
Stable nuclides are those whose n/p ratio isA. `n//p = 1`B. `n//p=2`C. `n//p gt 1`D. `n//p lt 1` |
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Answer» Correct Answer - A The `(n)/(p)` ratio of stable nuclide is = 1 |
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| 479. |
Smaller the value of half`-` life period, greater is the number of atoms that are disintegrating. |
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Answer» Correct Answer - T |
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| 480. |
Which of the following does not characterise X-raysA. The radiation can ionise gasesB. It casuses ZnS to fluorescenceC. Deflected by electric and magnetic fieldD. Have wavelengths shortest than ultraviolet rays |
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Answer» Correct Answer - C X-rays do not carry any charge and hence are not deflected by electric and magnetic fields |
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| 481. |
Gamma rays areA. High energy electromagnetic wavesB. High energy electronsC. High energy protonsD. Low energy electrons |
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Answer» Correct Answer - A `gamma`-rays are designated by hv |
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| 482. |
When the quantity of a radioactive substance is increased two times, the number of atoms disintegrating per unit time isA. DoubledB. Increased by square of twoC. Increased but not a great extentD. Not affected |
| Answer» Correct Answer - A | |
| 483. |
In the sequence of following nuclear reactions `._(92)X^(238) overset(-alpha)rarr Y overset(-beta)rarr Z overset(-beta)rarr L overset(-nalpha)rarr ._(84)M^(218)` the value of n will beA. 3B. 4C. 5D. 6 |
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Answer» Correct Answer - B The value of `n = (238 - 218)/(4) = (20)/(4) = 5 - 1 = 4` |
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| 484. |
The amount of energy, which is required to separate the nucleons from a nucleus is calledA. Binding energyB. Lattice energyC. Kinetic energyD. None of these |
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Answer» Correct Answer - A Definition of binding energy |
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| 485. |
Which of the following does not contain number of neutrons equal to that of `._(18)^(40Ar`A. `._(19)^(41)K`B. `._(21)^(43)Sc`C. `._(21)^(40)Sc`D. `._(20)^(42)Ca` |
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Answer» Correct Answer - C `._(18)^(40)Ar` has `40 - 18 = 22` neutrons While `._(21)^(40)Sc " has " 40 - 21 = 19` neutrons |
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| 486. |
An element group-III with atomic number 92 and mass number 238 undergoes decay of one `alpha` particle. The newely formed element belongs toA. IB. IIC. IIID. III |
| Answer» Correct Answer - c | |
| 487. |
Which statement is incorrectA. `alpha-`rays have more penetrating power than `beta-` raysB. `alpha-`rays have less penetrating power than `gamma-`raysC. `beta-`rays have less penetrating power than `gamma`-raysD. `beta-`rays have more penetrating power than `alpha`-rays |
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Answer» Correct Answer - A The order of penetrating power is : `alpha lt beta lt gamma-`rays. It is due to lower mass and high speed |
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| 488. |
Formation of nucleus from its nucleons is accompanied byA. Decrease in massB. Increase in massC. No change of massD. None of them |
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Answer» Correct Answer - A Due to mass decay |
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| 489. |
The proper rays for radiocarbon dating areA. UV-raysB. IR-raysC. Cosmic raysD. X-rays |
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Answer» Correct Answer - C The radioactive isotope `._(6)C^(14)` is produced in the atmosphere by the action of cosmic ray neutrons on `._(7)N^(14)` |
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| 490. |
In the following emission of `alphaa-` and `beta-` particle, groups `G""_(1),G""_(2),G""_(3)` and `G""_(4)` are `""_(92)""^(235)Uoverset(-alpha)toAoverset(-alpha)toBoverset(-alpha)toCoverset(-alpha)toD`A. IB VIIA VIIIA IAB. IB VIIA 0 IAC. IIIB IB IIB IIIBD. IIIB IA IIIB IIIB |
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Answer» Correct Answer - d `U""_(92)""^(238)-He""_(2)""^(4)toTh""_(92)""^(234)(III""_(B))` |
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| 491. |
The ratio of `C^(14)//C^(12)` in dead tissue is less than that in fresh tissue. |
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Answer» Correct Answer - T |
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| 492. |
Slow neutrons can bring about the fussion ofA. `._(92)U^(235)`B. `._(82)U^(238)`C. `._(82)Pb^(207)`D. `._(88)U^(226)` |
| Answer» Correct Answer - A | |
| 493. |
There are four radioactive decay series called thorium `(4n)`, uranium `(4n + 2)` actinium `(4n + 3)` and neptunium `(4n + 1)` series. Neptunium series is artificial while other three series are natural. The end productsd of each radioacitve decay series have stable nuclei. All natural decay series terminate at lead but neptunium or artificial series terminate at bismuth. The end product formed in the disintegration of `._(88)Ra^(222)` isA. `._(81)TI^(304)`B. `._(82)Pb^(206)`C. `._(86)Rn^(222)`D. `._(83)Bi^(207)` |
| Answer» Correct Answer - B | |
| 494. |
Neutrons are obtained byA. Bombardment of Ra with `beta-`particlesB. Bombardment of Be and `alpha`-particlesC. Radioactive disintegration of uraniumD. None of these |
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Answer» Correct Answer - B `._(4)Be^(9) + ._(2)He^(4) rarr ._(6)C^(12) + ._(0)n^(1)` |
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| 495. |
If a noble gas emits one `alpha-`particle then it will be shifted in groupA. 2B. 3C. 16D. 17 |
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Answer» Correct Answer - C Noble gases are group 18 elements. Emission of `alpha`-particles from the nuclide of noble gas will displace the daughter nuclide two places left to the parent nuclide that means it will be shifted in group 16 |
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| 496. |
If the disintegration constant of an isotope is `.1237 xx 10^(-4) "years"^(-1)`, then its half-life period will beA. 280 yearsB. 560 yearsC. 5600 yearsD. 2800 years |
| Answer» Correct Answer - C | |
| 497. |
A positron is as heavy as a proton. |
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Answer» Correct Answer - F |
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| 498. |
There are four radioactive decay series called thorium `(4n)`, uranium `(4n + 2)` actinium `(4n + 3)` and neptunium `(4n + 1)` series. Neptunium series is artificial while other three series are natural. The end productsd of each radioacitve decay series have stable nuclei. All natural decay series terminate at lead but neptunium or artificial series terminate at bismuth. `._(86)Rn^(219)` is a member of actinium series. Another member of same series isA. `._(92)U^(235)`B. `._(89)Ac^(222)`C. `._(90)Th^(212)`D. `._(84)Po^(212)` |
| Answer» Correct Answer - A | |
| 499. |
In the transformation of `._(92)^(235)U " to " ._(92)^(234)U`, if one emission is an `alpha-`particle, what should be the other emission (s)A. Two `beta^(-)`B. Two `beta^(-) and " one " beta^(+)`C. One `beta^(-) and " one " gamma`D. One `beta^(+) and " one " beta^(-)` |
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Answer» Correct Answer - A `._(92)^(238)U underset("emission")overset(1 alpha "Particle")rarr ._(92)^(234)Th underset("emission")overset2 beta ("Particles")rarr ._(92)^(234)U` |
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| 500. |
A radioactive element resembling iodine in properties isA. AstatineB. LeadC. RadiumD. Thorium |
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Answer» Correct Answer - A Astatine (At) resembles in properties with iodine |
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