InterviewSolution
Saved Bookmarks
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.
| 851. |
The de Broglie wavelength associated with particle isA. Directly proportional to its energyB. Directly proportional to momentumC. Inversely proportional to its energyD. Inversely proportional to momentum |
|
Answer» Correct Answer - D de-Broglie equation is `lambda=h/p` |
|
| 852. |
Calculate the no of protons, neutron and electron in `._(7)^(14)N^(3-)` ion |
|
Answer» No. of protons =atomic number `(Z) = 7` No. of protons `=(A-Z) = 14 - 7 = 7` No. of electrons in an ion `=Z+` magnitude of charge `= 7 +3 = 10` |
|
| 853. |
if electron , hydrogen , helium and neon nuclei are all moving with the velocity of light , then the wavelength associated with these particles are in the orderA. Electron gt hydrogen gt helium gt neonB. Electron gt helium gt hydrogen gt neonC. Electron gt hydrogen lt helium lt neonD. neon lt hydrogen lt helium lt electron |
|
Answer» Correct Answer - A `lambda prop 1/m , m_e lt m_H lt m_"He" lt m_"Ne"` |
|
| 854. |
What transition in the hydrogen spectrum would have the same wavelength as the Balmer transition `n=4` to `n=2` of `He^(+)` spectrum ?A. `n_(1) = 1, n_(2) = 2`B. `n_(1) = 2, n_(2) = 3`C. `n_(1) = 3, n_(2) = 2`D. `n_(1) =2, n_(2) = 4` |
|
Answer» Correct Answer - A `R xx Z^(2) [(1)/(n_(1)^(2))-(1)/(n_(2)^(2))] = R [(1)/(n_(1)^(2))-(1)/(n_(2)^(2))]` |
|
| 855. |
The wave number of first line in Balmer series of Hydrogen is `15,200cm^(-1)` the wave number of first line in Balmer series of `Be^(3+)`A. `2.43 xx 10^(5)cm^(-1)`B. `3.43 xx 10^(5)cm^(-1)`C. `4.43 xx 10^(5)cm^(-1)`D. `5.43 xx 10^(5)cm^(-1)` |
|
Answer» Correct Answer - A `bar(v) = bar(v)_(H) xx Z^(2)` |
|
| 856. |
What is the energy of photons that corresponds to a wave number of `2.5 xx 10^(-5)cm^(-1)`A. `2.5 xx 10^(-20)erg`B. `5.1xx 10^(-23)erg`C. `4.97 xx 10^(-21)erg`D. `8.5 xx 10^(-2)erg` |
|
Answer» Correct Answer - C `E = hc bar(v)` |
|
| 857. |
What is the energy of photons that corresponds to a wave number of `5 xx 10^(-5)m^(-1)`A. `99.384 xx 10^(-30)J`B. `993.84 xx 10^(-30)J`C. `9.9384 xx 10^(-30)J`D. `0.99384 xx 10^(-30)J` |
|
Answer» Correct Answer - C `E = hcbar(v)` |
|
| 858. |
Which set of quantum numbers for an electron of an atom is not possibleA. n=1, l=0 , m=0 , s=+1/2B. n=1, l=1 , m=1 , s=+1/2C. n=1, l=0 , m=0 , s=-1/2D. n=2, l=1 , m=-1 , s=+1/2 |
|
Answer» Correct Answer - B n=1 and l=1 not possible for s-orbitals |
|
| 859. |
Which of the following statement about the electromagnetic spectrum is not correct ?A. IR raditions have larger wavelength than cosmic raysB. The frequency of microwave is less than of UV raysC. X-rays have large wavelength than microwavesD. The velocity of X- rays is more than of microwaves |
| Answer» The velocity of X rays is more than that of microwaves. | |
| 860. |
Out of the following the radiation with lowest frequency isA. IR raysB. `gamma` RaysC. Cosmic raysD. Microwaves |
| Answer» Correct Answer - Microwaves | |
| 861. |
State which of the following sets of quantum number would be possible and which would not be permisible for an electron in an atom. (i) `n=3,I=3,m_(l)=+3, m_(s)=+(1)/(2)` (ii) `n=3,I=3,m_(l)=+1, m_(s)=-(1)/(2)` (iii) `n=5,I=4,m_(l)=+3, m_(s)=(1)` (iv) `n=0,I=0,m_(l)=0, m_(s)=+(1)/(2)` (v) `n=4,I=3,m_(l)=-2, m_(s)=-(1)/(2)` |
|
Answer» Correct Answer - (i) Not possible because when `n=3, I`cannot be equal to `3`. The value of `I` cannot be numerically equal to the value of `n`. (ii) Not possible because when `I=0,m_(I)` cannot be `+1` The value of `m_(1)` cannot be numerically mor than the value of `I`. (iii) Not possible because s cannot be 1 The only allowed values of `m_(s)` are `+(1)/(2)` and `-(1)/(2)` (iv) Not possible because n cannot be 0. (v) This set is permitted because when `n=4,I` can be 3. When `I=3, M_(1)` can be `-2. M_(s)` can have `-(1)/(2)` value |
|
| 862. |
Which set of quantum number is not possible for electron un `3^(rd)` shell ?A. `n = 3 l = 2 m = -1 s = + 1//2`B. `n = 3 l = 2 m = -1 s = - 1//2`C. `n = 3 l = 2 m = 0 s = + 1//2`D. `n = 3 l = 3 m = 0 s = - 1//2` |
|
Answer» Correct Answer - D (d) Value of `1` are given by `0` to `n - 1`. For an electron in `n = 3`. Value of `1` can be `0, 1` or `2`. |
|
| 863. |
The mass- charge ratio for `A^(Theta)` ion is `1.97 xx 10^(-7) kg C ^(-1)` .Calculate the mass of A atom |
|
Answer» Given `(m)/(e ) = 1.97 xx 10^(-7) (since e = 1.602 xx 10^(-19)C)` `therefore m = 1.97 xx 10^(-7) xx 1.602 xx 10^(-19) kg` `M = 3.16 xx 10^(-26) kg` |
|
| 864. |
The set of quantum numbers not possible to an electron isA. `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 l volue `=0,1,2,3,` upto (n-1) onlu |
|
| 865. |
The angular momentum J of the electron in a hydrogen atom is proportional to `n^(th)` power of r (radius of the orbit) where n is :-A. 1B. `-1`C. `(1)/(2)`D. None |
| Answer» Correct Answer - 3 | |
| 866. |
For a valid Bohr orbit , its circumference should be :A. `= n lambda`B. `= ( n -1 )lambda`C. `gt n lambda`D. `lt n lambda` |
|
Answer» Correct Answer - A |
|
| 867. |
If first ionisation potential of a hypothetical atom is `16 V`, then the first excitation potential will be :A. `10*2 eV`B. 12 eVC. 14 eVD. 16 eV |
| Answer» Correct Answer - 2 | |
| 868. |
1st excitation potential for the H-like (hypothetical) sample is 24 V. Then:A. ionisation energy of the sample is 36 eVB. ionisation energy of the sample is 32 eVC. binding energy of 3rd excited state is 2 eVD. 2nd excitation potential of the sample is `(32xx8)/(9)V` |
|
Answer» Correct Answer - B::C::D |
|
| 869. |
The number of electrons having `l = 0` chlorine atom `(Z = 17)` isA. 2B. 4C. 6D. 5 |
|
Answer» Correct Answer - C ( c)`Cl : 1 s^2, 2 s^2, 2 p^6, 3 s^2, 3 p^5` Six electrons `(1 s^2, 2 s^2, 3 s^2)` have `l = 0`. |
|
| 870. |
Assertion : The energy of an electron is largely determined by its principal quantum number. Reason : The principal quantum number n is a measure of the most probable distance of finding the electron around the nucleus.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 |
|
Answer» Correct Answer - A We know that principal quantum number represent the main energy level or energy shell. Since each energy level is associated with a definite amount of energy, this quantum numbers determines to a large extent energy of an electron. It also determines the average distance of an electron around the nucleus . Therefore both Assertion and Reason are true and the Reason is a correct explanation of the Assertion. |
|
| 871. |
The cation energy of an electron is largely determined by its principal quantum number. The principal quantum number `n` is a measure of the most probable distance of finding atomic the electron around the nucleus.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true but reason is not the correct explanation of the assertion.C. If assertion is true but reason is falseD. If assertion is false but reason is true. |
|
Answer» Correct Answer - A (a) We know that principal quantum number represent the main energy level or energy shell. Since each energy level is associated with a definite amount of energy. This quantum numbers determines to a large extent the energy of an electron. It also determines the average distance of an electron around the nucleus. Therefore both assertion and reason are true and the reason is the correct explanation of the assertion. |
|
| 872. |
The charge to mass ratio of `alpha-` particles is approximately to the charge to mass ratio of protons:A. HalfB. TwiceC. 4 timesD. 6 times |
|
Answer» Correct Answer - B e/m value of ion `=("magnitude of charge")/("mass number")` |
|
| 873. |
The energy of one quantum of light with a wavelength of `6500Å(1Å = 10^(-10)` cm)A. `9.04xx10^(-24)` JB. `3.02xx10^(-20)` JC. `3.06xx10^(-19)` JD. `6.02xx10^(-20)` J |
|
Answer» Correct Answer - C `E=hv=(hc)/lambda=(6.625xx10^(-34)xx3xx10^(8))/(6500xx10^(-10))` `E=3.06xx10^(-19)` J |
|
| 874. |
Wavelength of high enrgy trabsition fo H-atoms is ` 91 . 2 nm`. Calculate the corresponding wavelength of `He^(+)`. |
|
Answer» For H- atom : ` 1/( lambda_H) = R_H [ 1/n_1^2 - 1/n_2^2]` ..(1) From `He^+ ion ,` ` 1/( lambda_(He^+)) = R_H xx Z^2 [ 1/n_(2)] ` ` = 91. 2 xx 1/2^2 = 22 . 8 nm`. |
|
| 875. |
The wavelength of high energy transition of H atom is `91.2 nm` Calculate the corresponding wavelength of He atom |
|
Answer» Correct Answer - B ` (1)/(lambda) = R ((1)/(n_(1)^(2)) - (1)/(n_(2)^(2)))Z^(2)` For hydrogen atom `(1)/(91.2) = R ((1)/(n_(1)^(2)) - (1)/(n_(2)^(2)))Z^(2)` For `He^(Theta)` ` (1)/(lambda) = R ((1)/(n_(1)^(2)) - (1)/(n_(2)^(2)))Z^(2)` Dividing the equation we get `(lambda)/(91.2) = (1)/(4)` `lambda = 22.8 nm` |
|
| 876. |
If each hydrogen atom is excited by giveng ` 8. 4 eV` of energy , then the number fo spectral lines emeitted si equal to :A. ` 0`B. ` 2`C. ` 3`D. `4` |
|
Answer» Correct Answer - A For excitation fo electron from ground state the minimum energy needed is ` 10. 2 eV,` ` E_2 - E_1 =- 3.4 - ( - 13 . 6) `. |
|
| 877. |
Give the correct order of initials `T` (true) or `F` (false) for following statements :- (I) If an ion has `2` electrons in `K` shell, `8` electrons in `I`. Shell and `6` electrons in `M` shell, then number of `S` electrons present in that element is `6`. (II) The maximum number of electrons in a subshell is given by `2n^(2)` (III) If electron has magnetic quantum number `-1`, then it cannot be present in s-orbital. (IV) Only one radial node is present in `3p` orbital.A. `"TTFF"`B. `"FFTF"`C. `TFTT`D. `FFTF` |
|
Answer» Correct Answer - C `(1)/(lambda)=R_(H)[(1)/(n_(1)^(2))-(1)/(n_(2)^(2))]` for shortest wave length `n_(2) = oo, n_(1) = 2` `(1)/(lambda)=R_(H^(ƶ^(2)))[(1)/(4)-(1)/(oo)]" "lambda=(4)/(4R_(H))=(1)/(R_(H))=x` `(1)/(lambda)=R_(H^(ƶ^(2)))[(1)/(9)-(1)/(16)]" "(1)/(lambda)=R_(h^(X^(2)))[(7)/(9xx16)]` `lambda=(9xx16)/(9xx7)xx(1)/(R_(H))implies lambda=(16)/(7)x` |
|
| 878. |
What is the potential energy of an electron present in `N-` shell of the `Be^(3+)` ion ?A. `-3.4 eV`B. `-6.8 eV`C. `-13.6eV`D. `-27.2eV` |
|
Answer» Correct Answer - D `PE = 2(T.E) = 2 [(-13 xx Z^(2))/(n^(2))]` |
|
| 879. |
What is the distance of closest approach to the nucleus of an `alpha`partile which undergoes scattering by `180^(@)` is geiger-marsden experiment? |
|
Answer» Correct Answer - `r_(0)=4.13`fm For closest approch, `(1)/(2)mv^(2)=K(Zexxe)/(r_(0))` For Rutherford experiment ltBrgt `(1)/(2)mv^(2)=5.5MeV=5.5xx10^(6)xx1.6xx10^(-19)J=8.8xx10^(-13)J` `8.8xx10(-13)=(9xx10^(9)xx2xx79xx(1.6xx10^(-19))^(2))/(r_(0))` `r_(0)=4.136xx10^(-15)m` `r_(0)=4.13` fm |
|
| 880. |
The density of the nucleus isA. `10^8` kg / ccB. `10^(-8)` kg / ccC. `10^(-9)` kg / ccD. `10^11` kg / cc |
|
Answer» Correct Answer - D The density of neutrons is of the order `10^11` kg /cc. |
|
| 881. |
The wavelength associated with a holf ball weighing 200 g and moving with a speed of 5km/h is of the order of :A. `10^(-10)m`B. `10^(-20)m`C. `10^(-30)m`D. `10^(-40)m` |
| Answer» Correct Answer - C | |
| 882. |
Which is correct statement about proton?A. Proton is nucleus of deuteriumB. Proton is ionized hydrogen moleculeC. Proton is ionized hydrogen atomD. proton is `alpha` -particle |
|
Answer» Correct Answer - C Proton is the nucleus of H-atom (H - atom devoid of its electron) |
|
| 883. |
For a d electron the orbital angular momentum isA. `sqrt(6)((h)/(2pi))`B. `sqrt(2)((h)/(2pi))`C. `((h)/(2pi))`D. `2((h)/(2pi))` |
|
Answer» Correct Answer - A The orbital angular momentum is `(h)/(2pi) sqrt(l(l + 1))` The orbital angular momentum for an electron in d orbital `(l = 2)` is `(h)/(2pi) sqrt(l(l + 1)) = (h)/(2pi) sqrt(2(2 + 1)) = (h)/(2pi) sqrt(6)` |
|
| 884. |
The nucleus of the atom consists of:A. proton and neutronB. proton and electronC. Neutron and electronD. proton, neutron and electron |
|
Answer» Correct Answer - A It consists of proton and neutron and these are also known as nucleons. |
|
| 885. |
The angle made by angular momentum vector of an electron with Z-axis is.A. `cos theta = l//m`B. `cos theta = sqrt((l)/(m))`C. `cos theta = sqrt((l + 1)l)/(m)`D. `cos theta = (m)/(sqrt((l + 1)l))` |
|
Answer» Correct Answer - D (d) `Z` component of the angular momentum `L_Z = (mh)/(2 pi)` `L_Z = L cos theta = sqrt(l(l + 1)) cos theta (h)/(2 pi)` `:. sqrt(l(l +1)) cos theta = m` or `cos theta = (m)/(sqrt(l(l + 1))`. |
|
| 886. |
Calcultat the frequency of the spectral line emitted when the elercton in ` n= 3` in ` H-`atom de-excites to ground state ` R_H = 109737 cm^(-1)`. |
|
Answer» We know , ` 1/( lambda ) = R_H [ 1/n_1^2 - 1/n_2^2]` ` :. c/(lambda ) = v = R _H . C [ 1/n_1^2 - 1/n_2^2]` ` = 109737 xx 3. xx 10^(10) [ 1/1^2 - 1/3^2]` ` = 2 . 92 xx 10^(15) sec ^(-1)`. |
|
| 887. |
The wavelength of the radiations emitted when in a hydrogen atom electron falls from infinity to stationary state is ` : (R_H = 1. 097 xx10^7 m^(-1))` .A. `406 nm`B. `192 nm`C. `91 nm`D. `9.1 xx 10^-8 nm` |
|
Answer» Correct Answer - C ( c) `(1)/(lamda) = R[(1)/(n_1^2) - (1)/(n_2^2)]` `(1)/(lamda) = 1.097 xx 10^7 m^-1 [(1)/(1^2) - (1)/(oo^2)]` `:. lamda = 91 xx 10^-9 m` We know `10^-9 = 1nm` So `lamda = 91 nm`. |
|
| 888. |
Which of the following statement is correct in relation to the hydrogen atom :A. `3s`- orbital is lower in energy than `3p`-orbitalB. `3p`-orbital is lower in energy than `3d`-orbitalC. `3s` and `3p`-orbitals are of lower energy than `3d`-orbitalsD. `3s`, and `3p`-orbitals all have the same energy. |
|
Answer» Correct Answer - D (d) Sub shells of each shell in `H`= atom possess same energy level. |
|
| 889. |
Maximum number of electrons in a sub-shell with `l = 3` and `n = 4` is.A. 2B. 6C. 0D. 14 |
|
Answer» Correct Answer - D l=3 means f subshell maximum number of `e^-` in f subshell =14 |
|
| 890. |
Which of the following orbitals are symmetric about the y-axis ? A. `p_x`B. `p_y`C. `d_x^2 - y^2`D. `d_(xy)` |
|
Answer» Correct Answer - B (b) The `p_y` orbital is symmetric about the `y-"axis"`. |
|
| 891. |
Calculate de Broglie wavelength of an electron travelling at `1 %` of the speed of light.A. `2.73 xx 10^-24`B. `2.4 xx 10^-10`C. `242.2 xx 10^10`D. None of these |
|
Answer» Correct Answer - B (b) One percent of the speed of light is `v = ((1)/(100)) (3.00 xx 10^9 ms^-1)` =`(3.00 xx 10^8 ms^-1)` Momentum of the electron `(p) = mv` =`(9.11 xx 10^-31 kg)(3.00 xx 106 ms^-1)` =`2.73 xx 10^-24 kg ms^-1` The de-Broglie wavelength of this electron is `lamda = (h)/(p) = (6.626 xx 10^-34)/(2.73 xx 10^-24 kgms^-1)` `lamda = 2.424 xx 10^-10 m`. |
|
| 892. |
Find the e/m value of `alpha`-particle `(He^(+2))` w.r.t H-atom? |
| Answer» `e//m` value of `He^(+2) = (2)/(4) = 0.5` | |
| 893. |
Which of the follwong nuclear reactiosn will generate an isotope?A. Neutron particle emissionB. Positron emissionC. `alpha`-particle emissionD. `beta`-particle emission |
|
Answer» Correct Answer - A Isotopes are species are having same number of protons but different number of neutrons |
|
| 894. |
Give the number of identical orbitals is a given energy level and the values for their m quantum numbers |
|
Answer» Correct Answer - A For d orbitals `l = 2` Then number of d orbitals `= 2l + 1 = 5m` ` -2, -1,0, +1, +2` |
|
| 895. |
The ratio of the de Broglie wavelength of a proton and alpha particles will be `1:2` if theirA. Velocity are in the ratio `1:8`B. Velocity are in the ratio `8:1`C. Kinetic energ are in the ratio `1:64`D. Kinetic energ are in the ratio `1:256` |
|
Answer» `lambda = (h)/(mv),(lambda_(p))/(lambda_(d)) = (1)/(2) rArr ((mv)_(p))/((mv)_(a)) = (2)/(1)` `," m_(a) = 4m_(p) rArr (V_(p))/(V_(a)) = (8)/(1)` `(KE_(p))/(KE_(a))= (1//2m_(p)Vp^(2))/(1//2m_(p)V_(p^(2))) = (8^(2))/(4) = 16:1` |
|
| 896. |
In which of the following situations, the heavier of the two particles has smaller de broglie wavelength ? The two particleA. move with the same speedB. move with the same linear momentumC. move with the same kineric erngyD. have fallen throuh the same height |
| Answer» Correct Answer - A::C::D | |
| 897. |
The orbital angular mometum quantum number of the state `s_(2)` is |
|
Answer» Correct Answer - C `S_(2),i.e. 3p` For p orbital `l = 1 1` |
|
| 898. |
Which orbit of the following statement (s) is//are correct ?A. Electrons behavaves as a waveB. s-orbital is non-directionalC. An orbital can accommodate a maximum of two electron with parallel spinsD. The energies of the various sub-shell in the same shell are in the order `s gt p gt d gt f` |
|
Answer» Correct Answer - A::B Order of energies of different orbital is `s lt p lt d lt f` |
|
| 899. |
The maximum number of dectrens that can be accomodeated in an orbital isA. 1B. 3C. 2D. 4 |
|
Answer» Correct Answer - C `2`(Maximum two electron) |
|
| 900. |
Which orbit of the following is lower in energy in a many electron atom ?A. `2p`B. `3d`C. `4s`D. `5f` |
|
Answer» Correct Answer - A According to `(n +1)` rule For `2s , n = 2,l = 0` `n + 1 = 2` Similarly for `3d = (n + 1) = 3` `4s = (4 + 0) = 4` 5f rarr 5f = (5 + 3) =-- 8` `2s `is lower in energy |
|