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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.
| 1501. |
for which of the following species, the expression for the energy of electron in the `n^(th)[E_(n)=(13.6Z^(2))/(n^(2))eV" atom"^(-1)]` has the validity?A. TritiumB. `Li^(2+)`C. DeuteriumD. `He^(2+)` |
| Answer» Correct Answer - A::B::C | |
| 1502. |
What is the energy of photon from a laser that emits light at 632.8 nmA. `3.14 xx 10^(-19)J`B. `1.26 xx 10^(-31) J`C. `2.52 xx 10^(-33)J`D. `4.19 xx 10^(-40)J` |
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Answer» Correct Answer - A |
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| 1503. |
Which electronic transition in a hydrogen atom releases the greatest amount of energy?A. `n = 3 to n =2 `B. `n = 5 to n = 3`C. `n = 6 to n = 5 `D. `n = 3 to n = 6 ` |
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Answer» Correct Answer - A |
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| 1504. |
An electronic transition from 1s orbital of an atom causesA. Absorption of energyB. Release of energyC. Both release or absorption of energyD. Unpredictable |
| Answer» Correct Answer - A | |
| 1505. |
What is the frequency of light with a wavelength of 480 nmA. `1.60 xx 10^(-6)s^(-1)`B. `6.25 xx 10^(5)s^(-1)`C. `6.25 xx 10^(14) s^(-1)`D. `1.44 xx 10^(20) s^(-1)` |
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Answer» Correct Answer - C |
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| 1506. |
The mass of an electron is `9.1 xx 10^(-31)J`, if its K.E. is `3.0 xx 10^(-25)J`. Calculate its wavelength. |
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Answer» Since `K.E = (1)/(2)mv^(2)` `v = ((2K.E)/(m)) = ((2xx 3.0xx 10^(-25)kg m^(2)s^(-2))/(9.1 xx 10^(-31)))^(1/2) =812 ms^(-1)` `lambda = (h)/(mv) = (6.626 xx 10^(-34)Js)/((9.1 xx 10^(-31)kg)(813 ms^(-1)))` `= 8967 xx 10^(-10)m = 896.7 nm` |
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| 1507. |
Statement : For ` n=3,l` may be ` 0,1` and ` 2,` and m may be` 0, +- 1` and `+- 2`. Explanation : For each value of (n) there are ` 0` to ( n-1) possible values of `l ,` and for each value of `l` there are (0) to ` +- l` values of (m).A. If both (A) and (R) are correct and (R) is the correct reason for (A).B. If both (A) and (R) are correct but (R) is not the correct explanation for (A).C. If (A) is correct but (R) is incorrect.D. If (A) is incorrect but (R) is correct. |
| Answer» Correct Answer - C | |
| 1508. |
A proton and an alpha particle are accelerated through the same potential difference. The ratio of the wavelengths associated with the proton to that associated with the alpha particle isA. 4B. 2C. `sqrt(8)`D. `(1)/(sqrt(8))` |
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Answer» Correct Answer - C `lambda = (h)/(sqrt(2m.q.v))` |
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| 1509. |
The nature of anode rays depends uponA. Nature of gas filled in the discharge tubeB. Nature of electrodeC. Nature of metalD. None of these |
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Answer» Correct Answer - A anode rays are streams of positive ions |
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| 1510. |
What is the maximum number of emission lines when th eexcited electron of a H atom in`n = 6` drop to the ground state? |
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Answer» The number of line s producted when an electron from the nth shell to the ground state is `(n(n- 1))/(2)` So the required number of emission lines is `(6(6-1))/(2)= 15` |
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| 1511. |
The ionisation energy of H atom is `13.6 eV` The inoisation energy of `Li^(2+)` law will beA. 54.4 eVB. 122.4 eVC. 13.6 eVD. 27.2 eV |
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Answer» Correct Answer - 122.4 eV `E_(1) "for" Li^(2+) = E_(1) "for" H xx Z^(2)[ for Li,Z = 3] = 13.6 xx 9 = 122.4eV` |
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| 1512. |
Neutron is a fundamental particle carryingA. A charge of +1 unit and a mass of 1 unitB. No charge and a mass of 1 unitC. No charge and no massD. A charge of -1 and a mass of 1 unit |
| Answer» Correct Answer - B | |
| 1513. |
Heaviest particle isA. MesonB. NeutronC. ProtonD. Electron |
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Answer» Correct Answer - B Mass of neutron is greater than that of proton , meson and electron. Mass of neutron = mass of proton + mass of electron |
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| 1514. |
A beam of light has three `lambda, 4144 "Å", 4972 "Å" "and"6216 "Å"` with a total intensity of `3.6 xx10^(-3) Wm^(-2)` equally distributed amongst the three `lambda.` The beam falls normally on an area `1.0 cm^(2)` of a cleam metallic surface of work function 2.3 eV. Assume that there is no loss of light by reflection etc. Calculate the no. of photoelectrons emitted in 2 sec, in scientific notation,`x xx 10^(y)` find the value of y. |
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Answer» Correct Answer - 12 |
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| 1515. |
Values of the four quantum numbers for the last electron in the atom are n=4, l=1, m=+1 and s=-1/2. Atomic number of the atom will beA. 22B. 32C. 33D. 36 |
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Answer» Correct Answer - D Atomic number is 36 and element is Kr |
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| 1516. |
Which of the following statements is trueA. The Kinetic energy of an electron is inversely proportional to square of its momentumB. de-Broglie wavelength associated with a particle is directly proportional to its mass.C. de-Broglie wavelength associated with a particle is directly proportional to square of its velocityD. The wavelength associated with an electron is directly proportional to square root of accelerating potential |
| Answer» Correct Answer - A | |
| 1517. |
Cathode rays areA. positively charged particlesB. Negatively charged particlesC. Neutral particlesD. None of these |
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Answer» Correct Answer - B Cathode rays are made up of negatively charged particles (electrons , `e^-`) |
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| 1518. |
The average distance of electron from the nucleus in an atom is of the order ofA. `10^6` mB. `10^(-6)` mC. `10^(-10)` mD. `10^(-15)` m |
| Answer» Correct Answer - D | |
| 1519. |
Which phrase would be incorrect to useA. A molecule of a compoundB. A molecule of an elementC. An atom of an elementD. None of these |
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Answer» Correct Answer - B A molecule of an element is a incorrect statement. The correct statement is "an element of a molecule ". |
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| 1520. |
The total number of electrons present in all `s` orbitals, all the `p` orbitals, and all the `d` orbitals of cesium ion are, respectively,A. 8,26,10B. 10,24,20C. 8,22,24D. 12,20,22 |
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Answer» Correct Answer - B `(Cs_55)=1s^2, 2s^2, 2p^6 , 3s^2, 3p^6 , 3d^10 , 4s^2 4p^6 , 4d^10, 5s^2 , 5p^6, 6s^1` `Cs^(+)=1s^2, 2s^2, 2p^6, 3s^2, 3p^6,3d^10,4s^2, 4p^6,4d^10, 5s^2 , 5p^6` Total no. of `e^-` in s-orbitals =10 Total no. of `e^-` in p-orbitals =24 Total no. of `e^-` in d-orbitals =20 |
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| 1521. |
Photoelectron are liberated by altra voilet light of wavelength `3000Å`from a metallic surface for which the photoelectron thershold is `4000 Å` calculate de broglic wavelength of electron with maximum kinetic energy |
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Answer» KE = Quantum energy - Theshold energy = `(hc)/(lambda_(1)) - (hc)/(lambda_(2))` `= (6.626 xx 10^(-34) xx 3 xx 10^(8))/(3000 xx 10^(-10)) - (6.626 xx 10^(-34) xx 3 xx 10^(8))/(4000 xx 10^(-10)) ` `= (6.626 xx 10^(-34) xx 3 xx 10^(8))/(10^(-10)) ((1)/(3000) - (1)/(4000))` `= 1.656 xx 10^(-19) J` `1/2mv^(2)=1.656xx10^(-19)` `rArr m^(2)v^(2) = 2 xx 1.6565 xx 10^(-19) xx 9.1 xx 10^(-31)` `mv = 5.49 xx 10^(25)` `rArr lambda = (h)/(mv) = (6.626 xx 10^(-34))/(3.49 xx 10^(-25)) = 1.2 xx 10^(-9) m` |
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| 1522. |
In hydrogen spectyrum the series of lines appearing in altra violet region of electronmagnetic spectyrum are calledA. Balmer linesB. Lyman linesC. Pfund linesD. Brackett line |
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Answer» Correct Answer - B Lyman series |
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| 1523. |
Anode rays were discovered byA. GoldsteinB. J. StoneyC. RutherfordD. J.J. Thomson |
| Answer» Correct Answer - A | |
| 1524. |
Which of the following statements is (are) incorrect ?A. Atomic number = number of neutrons + number of electronsB. Mass number = number of protons + number of neutronsC. Atomic number = number of neutronsD. Atomic mass = number of neutrons |
| Answer» Correct Answer - A::C | |
| 1525. |
The numbers of protons , neutrons and electrons present in an atom of argon are , respectively ,A. 18,18 and 22B. 22,18 and 18C. 18,22 and 18D. 18,16 and 18 |
| Answer» Correct Answer - C | |
| 1526. |
The density of the nucleus isA. `2.4xx10^15 "kg m^(-3)`B. `2.4xx10^19 "kg m^(-3)`C. `2.4xx10^17 "kg m^(-3)`D. `2.4xx10^14 "kg m^(-3)` |
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Answer» Correct Answer - C `rho="Au"/(4/3pixx[1.2xx10^(-15)A^(1//3)]^(3))` `=u/(1.33pi(1.2xx10^(-15))^3)` `=(1.66xx10^(-24)kg)/(1.33pi(1.2xx10^(-15))^3m^3)=2.4xx10^17 kgm^(-3)` |
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| 1527. |
Splitting of signals is caused byA. protonB. neutronC. PositronD. Electron |
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Answer» Correct Answer - A Splitting of signals is caused by protons attached to adjacent carbon provided these are not equivalent to the absorbing proton. |
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| 1528. |
The `e//`m ratio for electron was determined by ……..A. J.J. ThomsonB. DaltonC. ChadwickD. Goldstein |
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Answer» Correct Answer - A e/m ratio (charge to mass ratio ) was determined by J.J. Thomson. |
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| 1529. |
Statement : Specific charge of ` alpha`-particles is twice to that of proton . Explanation : Specific charge is given by `e//m`A. S is correct but E is wrongB. S is wrong but E is correct.C. Both S and E are correct and E is correct explanation of SD. Both S and E are correct but E is not correct explanation of S |
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Answer» Correct Answer - B Specific Charge for proton =e/m and specific charge of `alpha=(2e)/(4m) =e/(2m)` |
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| 1530. |
The ratio of specific charge of a proton and an alpha-particle is :A. `2:1`B. `1:2`C. `1:4`D. `1:1` |
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Answer» Correct Answer - A Charge on proton =+1 unit , charge on `alpha` particle = +2 units, 2 :1 |
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| 1531. |
The specific charge of a proton is `9.6 xx 10^7 C kg^-1`, then for and `alpha-"particles"` it will be.A. `2.4 xx 10^7 C kg^-1`B. `4.8 xx 10^7 C kg^-1`C. `19.2 xx 10^7 C kg^-1`D. `38.4 xx 10^7 C kg^-1` |
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Answer» Correct Answer - B (b) For proton `e//m = 9.6 xx 10^7 C//kg` For a particle `= (2e)/(4 m) =(1)/(2) e//m` =`(1)/(2) xx 9.6 xx 10^7` =`4.8 xx 10^7 C//kg`. |
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| 1532. |
Which of the following particles is largely responsilbe for the chemical behaviour of elements ?A. ProtonB. ElectronC. NeutronD. Positron |
| Answer» Correct Answer - B::C | |
| 1533. |
what is the total number of orbitals associated with the principal quartum number n= 3? |
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Answer» For `n = 3`, the possible values of l are 0,1 and 2. Thus there is one 3s orbital `(n = 3, l = 1` and `m_(1) - 1,0,+1)`, there are five 3d orbitals `(n= 3, l = 2` and `m_(l) =- 2, -1,0,+1,+2)` The same value can also be obtained by using the relation, number of orbitals `=n^(2), i,e 3^(2) = 9` |
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| 1534. |
The atomic number of an element is 35. What is the toal number of electrons present in all the p-orbitals of the ground state atom of that element?A. 6B. 11C. 17D. 23 |
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Answer» Correct Answer - C `X_35=1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^5` Total no. of `e^-` is all p-orbitals =6+6+5=17 |
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| 1535. |
Bond dissociation energy of AB molecules is `300 kJ//"mole"`. The number of moles of photons of wavelength `6625 A^(0)` requires to dissociate 3 moles of AB molecules isA. 1B. 2C. 4D. 5 |
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Answer» Correct Answer - D `E = (Nhc)/(lambda)` |
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| 1536. |
The particles present in the nucleus of an atom areA. the proton and the electronB. the electron and the neutronC. the proton and the neutronD. none of these |
| Answer» Correct Answer - C | |
| 1537. |
The isotopes contain the same number of :A. neutronsB. protonsC. protons+neutronsD. electron |
| Answer» Correct Answer - B::D | |
| 1538. |
Number of electrons in `-CONH_2` isA. 22B. 24C. 20D. 28 |
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Answer» Correct Answer - B `-CONH_2`=6+8+7+2+1 (from other atom to form covalent bond )=24 |
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| 1539. |
The angular part of the wave function depends on the quantum numbers are:A. `n`B. `l`C. `m`D. `s` |
| Answer» Correct Answer - B::C | |
| 1540. |
Number of neutrons in heavy hydrogen atom is |
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Answer» Correct Answer - B Heavy hydrogen is `._1^2D` Number of neutrons =1 |
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| 1541. |
The number of neutrons in an atom of hydrogen isA. 1B. 2C. 0D. 3 |
| Answer» Correct Answer - C | |
| 1542. |
The atomic number of an element is always equal toA. Atomic weight divided by 2B. Number of neutrons in the nucleusC. Weight of the nucleusD. Electrical charge of the nucleus |
| Answer» Correct Answer - D | |
| 1543. |
`Be^(2+)` is isoelectronic withA. `Mg^(2+)`B. `Na^+`C. `Li^+`D. `H^+` |
| Answer» Correct Answer - C | |
| 1544. |
The charge of an electron is `-1.6 xx10^(-19)` C. The value of free charge on `Li^+` ion will beA. `3.6xx10^(-19)` CB. `1xx10^(-19)` CC. `1.6xx10^(-19)` CD. `2.6xx10^(-19)` C |
| Answer» Correct Answer - C | |
| 1545. |
The number of electrons in `[._19^40K]^(-1)` isA. 19B. 20C. 18D. 40 |
| Answer» Correct Answer - B | |
| 1546. |
Calculate frequency of revolution of electron in 4th Bohr orbit `Be^(+3)` ion . Given that `(pi^(2)me^(4)k^(2))/(h^(3)) = 1.62 xx10^(15) sec^(-1),` symbols have usual meaning. Express your answers in terms of `10^(15) sec^(-1).` Write the answer upto one significant figure. |
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Answer» Correct Answer - 2 |
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| 1547. |
The wavelength of the first member of the balmer series of hydrogen is `6563xx10^(-10)m`. Calculate the wavelength of its second member. |
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Answer» `(1)/(lamda_(1))=R_(H)[(1)/(2^(2))-(1)/(3^(2))] and (1)/(lamda_(2))=R_(H)[(1)/(2^(2))-(1)/(4^(2))]` `(lamda_(2))/(lamda_(1))=(5)/(36)xx(16)/(3)=(20)/(27)` `lamda_(2)=(20)/(27)xx6563xx10^(-10)=4861xx10^(-10)m`. |
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| 1548. |
According to qauntum mechanical model of H-like species, and electron can be represented by a wave function `(psi)` which contain all dynamic information about the electron. The nature of wave function depends on the type of the orbital to which the electron belongs. For an orbital `psi=[sqrt(2)/(81sqrt(3pi))]((1)/(a_(0)))^(3//2)(27-18sigma+2sigma^(2))e^((sigma)/(3))` Where, `sigma =((Zr)/(a_(0))),r` = radial distance from nucleous, `a_(0)=52.9pm` The orbital could possibly beA. `4s`B. `4p`C. `3s`D. `3p` |
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Answer» Correct Answer - C `therefore` It must be a 3s-orbital. |
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| 1549. |
In a hydrogen atom , which transition produces a photon with the highest energy ?A. `n = 3 to n =1 `B. `n = 5 to n = 3`C. `n= 12 to n = 10 `D. `n = 22 to n = 20 ` |
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Answer» Correct Answer - A |
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| 1550. |
In a hydrogen like sample two different types of photons A and B are produced by electronic transition. Photon B has its wavelength in infrared region. If photon A has more energy than B, then the photon may belong to the region:A. ultravioletB. visibleC. infraredD. far infrared |
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Answer» Correct Answer - a,b,c |
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