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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.
| 751. |
The change in velocity when hydrogen electron jumps from K shell to L shell isA. One-half of its original velocityB. Twice to its original velocityC. One-quarter of its original velocityD. Equal to its original velocity |
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Answer» Correct Answer - A `V_(n) = (v_(1))/(n)` |
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| 752. |
An electron jumps form `5^(th)` sehell to `2^(th)` shell . How many state fo transition are possinle ? |
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Answer» Correct Answer - 6 Niumber of possible transitions . ltbr. ` sum Delta n = sum ( 5 -2) = 1 + 2 +3 -6`. |
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| 753. |
The critical frequency for emitting photoellectrons from a metal surface is ` 5 xx 10^(14) sec ^(-1)`. What should be the frequency fo radiation to produce photoelectons having twice the kinetic energy of those produced by the radiation fo frequency ` 10^(15) sec ^(-1)` ? |
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Answer» Given critical frequency `= 5 xx 10^(14) sec^(-1)` When surface is exposed to frequency of ` 10^(15) sec^(-1)` Energy fo photon ` = hv_0 + K.E.` ` h xx 10^(15) = h xx 5 xx 10^(14) + K.E` ` therefore K.E. = 10 xx h xx 10^(14)` `= 5 xx h xx 10^(14)` ` = 5 xx h xx 10^(14)` Now for (II) case . if K.E. becomes twice of this then New ` K.E, = 2 xx 5 xx h xx 10^(14)` The energy of photon ` = hv_0 + K. E` ` hv= 5xx 10^(14) xx h + 2 xx 5 xx h xx 10^(14)` ` therefore v= 15 xx 10 ^(14) sec^(-1)` . |
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| 754. |
The maxium sum of number of neutrons and protons in an isotope of hydrogen is :A. `6`B. `5`C. `4`D. `3` |
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Answer» Correct Answer - D In `._1H^3` , nucleons are `3`. |
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| 755. |
The ratio of kinetic energy and potential energy of an electrron in an orbit is equato to :A. `0`B. `-0.5C. `-2`D. `prop` |
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Answer» Correct Answer - B `(KE)/(PE) = (-e^2 //2r)/(e^2//r) = - 1/2`. |
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| 756. |
Heisenberg uncertainty principle states that.A. Moving bodies exhibit both particle and wave characterB. Neither the position nor the momentum of a particle can be precisely determined.C. Simultaneous determination of position and momentum of a microscopic particle is not possible.D. Moving charged particles resemble electromagnetic waves in their behaviour. |
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Answer» Correct Answer - C ( c) Simultaneous determination of position and momentum (or velocity) of a microscopic particle is not possible. |
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| 757. |
The maxium value of l for n =4 isA. 2B. 4C. 3D. 5 |
| Answer» Correct Answer - C | |
| 758. |
Any two electron in an atom can have maxium of three quantam numbers same |
| Answer» Correct Answer - Ture | |
| 759. |
Heisenberg uncertainty principal is not valid forA. Moving electronB. Motor carC. Stationary particlesD. All of the BOVE |
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Answer» Correct Answer - B::C Heisenberg principal is only for microscopic particles which are moving with very light speed |
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| 760. |
In the spectrum of visible light , the red light has maximum ……… and …….. Minimum |
| Answer» Wavelength, frequency | |
| 761. |
What is the maxiumum number of electron , present in an orbit whose angular momentmum is `(2h)/(pi)`A. 18B. 2C. 32D. 8 |
| Answer» Correct Answer - C | |
| 762. |
The first use of quantam theroy to explain the structure of atom was made by :A. HeisenburgB. BhorC. planckD. Einstein |
| Answer» Correct Answer - B | |
| 763. |
Which of the following sets of quantam numbers represent electron in hydrozen atomA. 1,1,0 `+(1//2)`B. 1,0,0, `+(1//2)`C. 3,0,0 `-(1//2)`D. 4,2,1 `-(1//2)` |
| Answer» Correct Answer - B | |
| 764. |
The azimuthal quantam number of an electron is zero , then the shape of its orbitals will beA. circularB. sphericalC. ellipticalD. dumbbell |
| Answer» When l=0 , the shape the shape of the orbital IS spherical (s orbital). | |
| 765. |
Which orbit would be the first to have `g` subshell :-A. `3^(rd)`B. `4^(th)`C. `5^(th)`D. `6^(th)` |
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Answer» Correct Answer - C From `(n+l)` rule, same as `Q.23` |
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| 766. |
Zeeman and Stark effects can be explained by _ quantam numberA. principalB. azimuthalC. magneticD. spin |
| Answer» Correct Answer - C | |
| 767. |
Which of the following statement are correct for an electron that has `n = 4` and `m = - 27`A. The electron may be in a d-orbitalB. The electron in the fourth principal electyronic shellC. The electron may be in a p- orbitalD. The electron must have the spin quantum number `= + 1//2` |
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Answer» Correct Answer - B::D `n = 4` (principal shell) `n = - 2` `s = + 1//2` |
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| 768. |
The velocity of all electromagnetic radiation is ……….. |
| Answer» `3 xx 10^(6) m s^(-1)` | |
| 769. |
The wave charaters of electron was experimenally verified by ………..A. De BroglieB. Devision and germerC. G.P ThomsonD. Rutherford |
| Answer» Correct Answer - A::B | |
| 770. |
Of the following which of the statement (s) regarding Bohr theory is woring ?A. kinetic energy of an electron is half of the magnitude of its potential energyB. Kinetic energy of an electron is negative of total energy electronC. Energy of electron decreases with increase in the value of the principal qwuantum bnumberD. The ionization enrgy fo H-atom in the first excited state is negative fo one fourth of the enrgy of an elecron in the ground state , |
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Answer» Correct Answer - C Energy of electron increases with inrcease in `[E_n prop - 1/n^2]`. |
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| 771. |
How many electron in an atom with atomic number `105` can have `(n + l) = 8` ?A. 30B. 17C. 15D. Unpredictable |
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Answer» Correct Answer - B `5f^(14),6a^(3) rArr 17:e^(-)` `5f^(14)= (n + 1) = 5 + 3 = 8` `6d^(3) = (n + 1) = 6 + 2 = 8` |
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| 772. |
The shape of the orbital is determined byA. spin quantum numberB. magnetic quantum numberC. azimuthal quantum numberD. principal qunatum number |
| Answer» Correct Answer - C | |
| 773. |
The set of quantum not applicable to an electronA. `1,1,1+1//2`B. `1,0,0,+1//2`C. `1,0,0,-1//2`D. `2,0,0,+1//2` |
| Answer» Correct Answer - A | |
| 774. |
Which of the following set of quantum number is not applicable for an electron in an atom?A. `n=2l=0m=0s=+1//2`B. `n=1 l=0 m=0 s=-1//2`C. `n=1l=0m=0s=+1//2`D. `n=1l=1m=1s=+1//2` |
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Answer» Correct Answer - D For `n=1 l=1` not possible Since, `l=0 to (n-1)` |
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| 775. |
Choose the incorrect statements:A. The shape of an atomic orbital depends upon the azimuthal quantum numberB. The orientation of an atomic orbitals depend upon the magnetic quantum numberC. The energy of an electron in an atomic orbital of multi-electron atom depends on principal quantum numberD. The number of degenerate atomic orbitals of one type depends on the value of azimuthal and magnetic quantum numbers |
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Answer» Correct Answer - C n,l,m represent size, shape dixection of orbital |
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| 776. |
Wave functions of electrons in atoms and molecules are called ………….. |
| Answer» Correct Answer - Orbitals | |
| 777. |
The shape of s-orbital isA. PyramidalB. SphericalC. TetrahedralD. Dumb-bell shaped |
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Answer» Correct Answer - B The s-orbital has spherical shape due to its non-directional nature. |
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| 778. |
Assertion : Two electrons in an atom can have the same values of four quantum numbers. Reason : Two electrons in an atom can be present in the same shell, sub-shell and orbital and have the same spin.A. If both assertion and reason are true and the reason is the correct explanation of the assertionB. If both assertion and reason are true but reason is not the correct explanation of the assertionC. If assertion is true but reason is falseD. If the assertion and reason both are false |
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Answer» Correct Answer - D We know from the Pauli exclusion principle, that two electrons in the same atom can not have same value of all four quantum numbers. This means each electron in an atom has only one set of values of n,l,m and s. Therefore both the Assertion and Reason are false. |
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| 779. |
Assertion: Spin quantum number can have the value +1/2 or -1/2. Reason:(+) sign here signifies the wave function.A. If both assertion and reason are true and the reason is the correct explanation of the assertionB. If both assertion and reason are true but reason is not the correct explanation of the assertionC. If assertion is true but reason is falseD. If the assertion and reason both are false |
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Answer» Correct Answer - C Assertion is true but reason is false. Spin angular momentum of the electron, a vector quantity, can have two orientations (represented by + and - sign) relative to a chosen axis. These two orientation are distinguished by the spin quantum number `m_s` equals to `+1/2` or `-1/2`.These are called the two spin states of the electron and are normally represented by the two arrows `uarr` (spin up) and `darr` (spin down ) respectively. |
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| 780. |
(A) `3d_(z^(2))` orbital is spherically symmetrical. (R) `3d_(z^(2))` orbital is the only d-orbital which is spherical in shape.A. If both assertion and reason are true and the reason is the correct explanation of the assertionB. If both assertion and reason are true but reason is not the correct explanation of the assertionC. If assertion is true but reason is falseD. If the assertion and reason both are false |
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Answer» Correct Answer - D Both assertion and Reason are false . Only s-orbital is spherically symmetrical . Shape of different d orbital is double dumb-bell |
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| 781. |
Which of the following orbitals does not have the angular node ?A. `P_(x)` orbitalB. `d_(x^(2)` orbitalC. `P_(y)` orbitalD. `1s` orbital |
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Answer» Correct Answer - D x orbitals are independent of wave function .Thus , they do not have any angular node .They have only spectrical node .The number of spectrical nodes in s orbital are given by `(n - 1)` where n is the principal quantum number |
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| 782. |
The charge on `alpha` particle is ………The charge on proton |
| Answer» Correct Answer - Twice | |
| 783. |
An electron has spin quantum number (s) `+ 1//2` and magnetic quantum number is `1` it can be person inA. s orbitalB. d orbitalC. p orbitalD. f orbital |
| Answer» Correct Answer - B::C::D | |
| 784. |
Which of the following parameters are not same for all hydrogen like atom and lons is their ground state ?A. Radius of orbitB. Speed of electronC. Energy of the atomD. Orbital angular momentum of electron |
| Answer» Correct Answer - a,b,c | |
| 785. |
The hydrogen -like species `Li^(2+)` is in a spherically symmetric state `S_(1)` with one node. Upon absorbing light , the ion undergoes transition to a state `S_(2)`. The state `S_(2)` has one radial node and its energy is equal is to the ground state energy of the hydrogen atom. Energy of the state `S_(1)` in units of the hydrogen atom ground state energy isA. `0.75`B. `1.50`C. `2.25`D. `4.50` |
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Answer» Spherically symmetrical state (i.e.s orbital ) with one radial node `= 2s = s_(1)` `(n- l- 1) ` `n = 2 rarr s_(2)("one nodial node") = n_(2)` and `(E_(n))_(li^(2+)) = (E)_(1H)` `rArr -13.6 xx (3^(2))/(n_(2)^(2))= -13.6 xx (1^(2))/(1^(2))` `rArr n_(2) = 3` ` rArr s_(2) = 3p` `rArr (E_(s_(1))/(E_(H)))_(n=1)= (-13.6 xx (3^(2))/(2^(2)))/(-13.6 xx (1^(2))/(1^(2))) = 2.25` |
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| 786. |
If the radius of first second third and thurth orbit of hydrogen atom are `r_(1),r_(2),r_(3) and r_(4)` respectively .Then their current increases order will beA. `r_(4)` `lt`` r_(3)` `lt` `r_(2)` `lt``r_(1)`B. `r_(1)` `lt` `r_(2)` `lt` `r_(3)` `lt``r_(4)`C. `r_(4)` `lt` `r_(3)` `lt` `r_(2)` `gt``r_(1)`D. Equal in all |
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Answer» Correct Answer - `r_(1)` `lt` `r_(2)` `lt` `r_(3)` `lt``r_(4)` `r = n^(2)` `r_(1)` lt r_(2)` lt `r_(3)` lt`r_(4)` |
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| 787. |
The relation between radius of third orbit `r_(3)` and radius of first orbit `r_(1)` in hydrogen atom would beA. `r_(3)=3r_(1)`B. `r_(3)=9r_(1)`C. `r_(1)=3r_(3)`D. `r_(1)=9r_(3)` |
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Answer» Correct Answer - B `r=(n^(2)h^(2))/(4pi^(2)me^(2)z) i.e r propn^(2)` |
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| 788. |
Consider the hydrogen atom to be a proton embededded in a cavity of radius (Bohr radius) whose charge is neutralised by the addition of an electron to the cavity in a vacume innitially slowly .Extimate the average total energy of an electron in its ground state in a hydrogen atom as the work done in the above neutrallisation process .Also if the magnitude of teh average kinetic enerhy is half the magnitude of teh average potenrtial energy .Find teh average potential energy |
| Answer» Correct Answer - A::B::C | |
| 789. |
Suppose a completely filled or half fillled set fo ( p) or d-orbitials is spherically symmetrical :A. `o`B. `3`C. `1`D. `4` |
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Answer» Correct Answer - C `CI^(-)` has ` ns^2 np^6` configuration . |
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| 790. |
The frequency of radiations emitted when electron falls from `n = 4` to `n = 1` in `H-"atom"` would be (Given `E_1` for `H = 2.18 xx 10^-18 J "atom"^-1` and `h = 6.625 xx 10^-34 Js`.)A. `1.54 xx10^(15) s^(-1)`B. `1.03xx10^(15) s^(-1)`C. `3.08xx10^(15) s^(-1)`D. `2.00xx10^(15)s^(-1)` |
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Answer» Correct Answer - C (c) Ionisation energy of H `=2.18xx10^(-18) J "atom"^(-1)` `:. E_(1)`(Energy of Ist orbit of H-atom) =`- 2.18 xx 10^(-18) J "atom"^(-1)` `:. E_(n)=(-2.18xx10^(-18))/(n^(2)) J "atom"^(-1)` Z=1 for H-atom `DeltaE=E_(4)-E_(1)` `=(-2.18xx10^(-18))/(4^(2))-(-2.18xx10^(-18))/(1^(2))` `=-2.18xx10^(-18)xx[(1)/(4^(2))-(1)/(1^(2))]` `DeltaE=-2.18xx10^(-18)xx-(15)/(16)` `=+2.0437xx10^(-18) J "atom"^(-1)` `:. v=(DeltaE)/(h)` `=(2.0437xx10^(-18)J "atom"^(-1))/(6.625xx10^(-34) Js)` `=3.084xx10^(15)s^(-1) "atom"^(-1)` |
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| 791. |
Isotopes of an element are the atoms which haveA. the same number of protons in their nucleiB. the same number of protons in their nucleiC. the same mass numberD. different number of electrons in their orbits. |
| Answer» Correct Answer - B | |
| 792. |
Isotopes are those atoms which have same ……….. |
| Answer» Correct Answer - Atomic number | |
| 793. |
The atoms of various isotopes of a particular element differ from each other in the number of:A. electrons in the outer shell onlyB. protons in the nucleusC. electrons in the inner shell onlyD. neutrons in the nucleus. |
| Answer» Correct Answer - D | |
| 794. |
The wavelength of particular radiation is `700 " nm" (1" nm"-10^(-9)"m")`.Find its frequency (v). |
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Answer» `lambda=700 nm =700 xx10^(-9)m=7xx10^(-7)m`. Also , `c="velocity of light" =3xx10^8m//s`. So, `v=(c)/(lambda) =(3xx10^8)/(7xx10^-7)=0.42xx10^15//s` |
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| 795. |
The isotopes of an element have mass numbers, `A,A+1,A+2`. The ratio of abundance of these isotopes is `3:2:4`. Calcualte the average atomic mass of the element. |
| Answer» Average atomic mass `=(Axx3+(A+1)2+(A+2)4)/(9)=(3A+2A+2+4A+8)/(9)=A+(10)/(9)` | |
| 796. |
How many protons and neutrons are there in the following nuclel ? `._(6)C^(12),_(8)C^(17),_(12)Mg^(25), _(26)Fe^(56),_(38Sr^(88))` |
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Answer» `._(6)C^(12)` Number of proton `= 6` Number of neutrons `= 12 - 6 = 6` b.`._(8)C^(17)` Number of proton `= 8` Number of neutrons `= 17 - 8 = 9` c..`._(12)Mg^(25)` Number of proton `= 12` Number of neutrons `= 25 - 12 = 13` d.`._(26)Fe^(56)` Number of proton `= 26` Number of neutrons `= 56 - 26 = 30` e.`._(38)Sr^(88)` Number of proton `= 38` Number of neutrons `= 68 - 38 = 50` |
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| 797. |
The energy of an electron in a particular orbit of `Li^(+2)` is -30.6 eV. What is the energy of an electron in the same orbit of `Be^(+3)` ? |
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Answer» (i) comparison of atomic numbers (ii) -54.4 eV |
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| 798. |
Wavelength of particular transition for `H` atom is `400 nm`. What can be wavelength of `He` for same transition ?A. `400 nm`B. `100 nm`C. `1600 nm`D. `200 nm` |
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Answer» Correct Answer - B (b) `(1)/(lamda) = R ((1)/(m^2) -(1)/(n^2)) xx Z^2` for `lamda_(He) = (400)/(2^2) = (400)/(4) = 100 nm`. |
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| 799. |
How many electrons are present in the M-shell of an atom of the element with atomic number `Z = 24`?A. 5B. 6C. 12D. 13 |
| Answer» Correct Answer - D | |
| 800. |
An atom of an element has two electrons in the valence shell and two consecutive inner shells have 8 electrons each. Calculate the atomic number of the element.A. 19B. 20C. 30D. 18 |
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Answer» Correct Answer - B Electronic configuration of atom of element which has two electrons in the valence shell and two consecutive inner shells have 8 electrons each is 2,8,8,2. And hence atomic number is element=20 |
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