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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.
| 1401. |
A chemist was performing an experiment to study the effect of varying voltage on the velocity and de Broglie wavelength of the electrons. In first experiment, the electron was accelerated through a potential difference of 1kV and in second experiment, it was accelerated through a potential difference of 2kV. The wavelength of de Broglie waves associated with electron is given by: `lamda=(h)/(sqrt(2qVm))` where, V is the voltage through which an electron is accelerated. Putting the values of h, m and q we get: `lamda=(12.3)/(sqrt(V))`Ã… Q. In order to get half velocity of electrons in second case, the applied potential will be:A. 0.25 kVB. 2 kVC. 0.5 kVD. 0.75 kV |
| Answer» Correct Answer - a | |
| 1402. |
The total number of m values for `n = 4` isA. 8B. 16C. 12D. 20 |
| Answer» Correct Answer - B | |
| 1403. |
Orbital is the region in an atom where the probability of finding the electron around the nucleus. Orbitals do not specify a definite path according to the uncertainty principle. An orbital is described with the help of wave function `Phi`. Whenever an electron is described by a wave function, we say that an electron occupies that orbital. Since, many wave functions are possible for an electron, there are many atomic orbitals in an atom. Orbitals have different shapes, except s-orbitals, all other orbitals hae different shapes, except s-orbitals, all other orbital have different shapes, except s-orbitals, all other orbitals have directional character. Number of spherical nodes in an orbital is equal to `(n-l-1)`. Orbital angular momentum of an electron is `sqrt(l(l+1))h`. Q. Which of thef ollowing orbitals is not cylinderically symmetrical about z-axis?A. `3d_(z^(2))`B. `4p_(z)`C. `6s`D. `3d_(yz)` |
| Answer» Correct Answer - D | |
| 1404. |
Statement-1: Cesium is useful as electrodes in photoelectric cells. Statement-2: Light energy absorbed by cesium is sufficient to make an atom of cesium to lose an electron.A. Statement-1 is true, statement-2 is true, statement-2 is a correct explanation for statement-1B. Statement-1 is true, statement-2 is true, statement-2 is not a correct explanation for statement-1C. Statement-1 is true, statement-2 is false.D. Statement-1 is false, statement-2 is true. |
| Answer» Correct Answer - B | |
| 1405. |
The angular momentum of an electron depends on:A. principal quantum numberB. azimuthal quantum numberC. magnetic quantum numberD. all of the above |
| Answer» Correct Answer - B | |
| 1406. |
Orbital angular momentum depends on .........A. lB. n and lC. n and mD. m and s |
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Answer» Correct Answer - C orbital angular momentum `=sqrt(l(l+1)) (h)/(2pi)` |
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| 1407. |
Orbital is the region in an atom where the probability of finding the electron around the nucleus. Orbitals do not specify a definite path according to the uncertainty principle. An orbital is described with the help of wave function `Phi`. Whenever an electron is described by a wave function, we say that an electron occupies that orbital. Since, many wave functions are possible for an electron, there are many atomic orbitals in an atom. Orbitals have different shapes, except s-orbitals, all other orbitals hae different shapes, except s-orbitals, all other orbital have different shapes, except s-orbitals, all other orbitals have directional character. Number of spherical nodes in an orbital is equal to `(n-l-1)`. Orbital angular momentum of an electron is `sqrt(l(l+1))h`. Q. The nodes present in 5p-orbital are:A. one planar, five sphericalB. one planar, four sphericalC. one planar, three spheicalD. four spherical |
| Answer» Correct Answer - C | |
| 1408. |
A chemist was performing an experiment to study the effect of varying voltage on the velocity and de Broglie wavelength of the electrons. In first experiment, the electron was accelerated through a potential difference of 1kV and in second experiment, it was accelerated through a potential difference of 2kV. The wavelength of de Broglie waves associated with electron is given by: `lamda=(h)/(sqrt(2qVm))` where, V is the voltage through which an electron is accelerated. Putting the values of h, m and q we get: `lamda=(12.3)/(sqrt(V))`Ã… Q. The wavelength of electron will be:A. 1.4 times in first case than in second caseB. 1.4 times in second case than in first caseC. double in second case than in first caseD. double in first case than in second case |
| Answer» Correct Answer - a | |
| 1409. |
The angular momentum of an electron in an atom depends onA. mB. lC. nD. All |
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Answer» Correct Answer - B orbital angular momentum `= sqrt(l(l+1)) (h)/(2pi)` |
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| 1410. |
Electronic energy is a negative energy becauseA. Electron carries negative chargeB. Energy is zero near the nucless and decreases as the distance from the nucless increasesC. Energy is zero at infinite distance from the nucless and decreases as the electron comes to the nuclessD. There are interelectronic repulsions |
| Answer» Energy is zero at infinite distance from the nucless and decreases as the electron comes to the nucless | |
| 1411. |
The nucleus of an atom is lecated at `x= y= z = 0` a. If the probability of finding an x electron in a tiny volume around `x= a,y = z = 0 ` is `1.0 xx 10^(-5)` what is the produbility of finding the electron in the same sized volume around `x = z = 0 = a`? b. what will be the probility as the second size if the electrns is in p orbital ? Explain |
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Answer» The distance of s orbital `1.0 xx 10^(-3)` is the same for two volumes is (i.e. `s= a,y = a,a= 1.0 xx 10^(-3))` and the s orbital is spherecally symmetrical hence the probility of finding the electron in each of two solutions is same b. Since the `p_(2)` orbital has a nodfe at `z= 0` the probability of finding the electron in this volume is zero |
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| 1412. |
A chemist was performing an experiment to study the effect of varying voltage on the velocity and de Broglie wavelength of the electrons. In first experiment, the electron was accelerated through a potential difference of 1kV and in second experiment, it was accelerated through a potential difference of 2kV. The wavelength of de Broglie waves associated with electron is given by: `lamda=(h)/(sqrt(2qVm))` where, V is the voltage through which an electron is accelerated. Putting the values of h, m and q we get: `lamda=(12.3)/(sqrt(V))`Ã… Q. The velocity of electron will be:A. same in bothB. 1.4 times in second experiment than in first experimentC. double in second experiment than in first experimentD. four tiems in the second case than in first case. |
| Answer» Correct Answer - b | |
| 1413. |
The quantum number which determines the energy of a sublevel isA. nB. lC. Both n and lD. Neither n nor l |
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Answer» Correct Answer - C `(n+l)` rule |
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| 1414. |
The quantum number l and the number of electrons (n) in the sub level are related byA. `n = 2l +1`B. `l = 2n +1`C. `n = 4l +2`D. `n = 2l^(2)` |
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Answer» Correct Answer - C max `e^(-)` in a sublevel `= 4l +2` |
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| 1415. |
According to Schrodinger model nature of electron in an atom is as :-A. Particles onlyB. Wave onlyC. Both simultaneouslyD. Sometimes waves and sometimes particle |
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Answer» Correct Answer - B The maximum porbability of finding an electron is describe the orbital, which is denote by `Psi^(2)` |
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| 1416. |
Among the various quantum numbers (n,l,m, s) describing an electron which can have the largest valueA. nB. lC. mD. s |
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Answer» Correct Answer - A n value represent orbit or shell |
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| 1417. |
Which one pair of atoms or ions will have same configuration ?A. `F^+` and NeB. `Li^+` and `He^-`C. `Cl^-` and `Ar`D. Na and K |
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Answer» Correct Answer - C No. of electron are same (18) in `Cl^-` and Ar |
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| 1418. |
Calculate the radius of the third orbit of a hydrogen atom the radius of the first Bohr of hydrogen atom is `0.53 Å` |
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Answer» We know that `v_(n) = n^(2)r_(0) = (3)^(2) xx 0.53 = 4.77 Å` |
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| 1419. |
In hydrogen atom are excited in the fifth level .The number of line that appear in the spectrum will beA. 4B. 8C. 10D. 12 |
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Answer» Number of lines produced for a juimp from orbit to first orbit is given by `(n-1)//2` required of lines `= (5(5- 1))/(2) = 10` |
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| 1420. |
The de-Broglie equation appliesA. To electrons onlyB. To neutrons onlyC. To protons onlyD. All the material object in motion |
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Answer» Correct Answer - D de-Broglie equation applies to all the material object in motion |
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| 1421. |
Calculate the ratio of the wavelength of the first and the nltimate line of the ballmer of `Li^(2+)` ? |
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Answer» Wavelength of the first line of the balmer series `n_(1) = 2 and n_(2) = 3` `bar v _(1)= RZ^(2)[(1)/(2^(2)) - (1)/(3^(2))] = ( 5 xx 5R)/(36) = (5R)/(4)` :. Wavelength of the first line of the bakmer series `= (4)/(5R)` Wavelength of alitimate line (limiting line) of the balmer series `bar v _(2) = RZ^(2)[(1)/(2^(2)) - (1)/(oo)] = (9R)/(4)` Wavelength of the altimate line of the balmer series `= (4)/(9R)` `:. Ratio = (9)/(5)` |
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| 1422. |
The quantum number which determines the number of sub-energy levels in any main energy level isA. nB. 1C. mD. s |
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Answer» Correct Answer - A No of sub energy levels =n |
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| 1423. |
The frequency of the strong yellow line in the spectrum of sodium in `5.09 xx 10^(14)s^(-1)` .Calculate the wavelength of the light nanometres |
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Answer» `lambda = (c )/(v) = (3.00 xx 10^(8) m s^(-1))/( 5.09 xx 10^(14) s^(-1))` `= 589 xx 10^(-9) m = 589 nm` |
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| 1424. |
Which of the d orbitals lies in the xy-plane ?A. `d_(xz)`B. `d_(xy)`C. `d_(x^(2)-y^(2)`D. `d_(xy) and d_(x^(2) - y^(2)` |
| Answer» The`d_(x^(2)-y^(2)` orbital lies in the xy plane | |
| 1425. |
The paoli exclasion principal applies toA. HB. `H^(o+)`C. `H^(o+)`D. None of these |
| Answer» Since H has one electron and `H^(o+)` has no electron , the pondi exclasion principal does not apply to them .However `H^(Theta)` has two electron hence this principal applies on it . | |
| 1426. |
Which of the following is not a charcleristic both as an motion and as a stream of particles?A. InterferenceB. `E = mc^(2)`C. DiffractionD. `E = hv` |
| Answer» Correct Answer - `E = hv` | |
| 1427. |
Two atoms are said to be isobars isA. they have same atomic number but different mass numberB. they have same number of electrons but different number of neutronsC. they have same number of neutrons but different number of electronsD. sum of the number of protons and neutrons is same but the number of protons is different |
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Answer» Correct Answer - D Isobars have same mass number but different no of protons |
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| 1428. |
An electron jumps from nth level to the first level .The correct face (s) about H atomic is//areA. Number of spectrum lines `= (n(n-1))/(2)`B. If `n = 4`number of spectrum lines `= 6`C. Number of spectrum lines `= (n(n-1))/(2)`D. If `n = 4` number of spectrum lines `= 10` |
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Answer» a.Correct b. correct`(4(4-1))/(4) = 6` c. and d are wrong |
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| 1429. |
The electron of H-atom in the ground state is excited to a higher energy level by monuchromatic light of energy `13.22 eV` How many different photon are emitted when it return to the ground state?A. 4B. 10C. 6D. 15 |
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Answer» `13.22eV = 13.6 [(1)/(1^(2)) - (1)/(n^(2))] = 13.6 - (13.6)/(n^(2))` ` (13.6)/n^(2)=13.6-13.22=0.38` `n = 6` The electron of H atom is axcited from `n_(1) rarr 1 "to" n_(2) rarr 6` Number of line `= (6(6-1))/(1) = 15` The number of photon emitted is equal to the number of spectral lines `= 15` |
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| 1430. |
What would be the uncertaininty in momentum of an electron whose powsition is known with absolute certaity ? |
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Answer» Correct Answer - A The uncertaintuy in momentum would be infinite |
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| 1431. |
Describe the difference between the properies of line electron and a moving circket hall . |
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Answer» Correct Answer - A Free electron have dual character i.e . Wave charadcter as well as partilce character whereas a cricket ball has predominatly particle charadcter b. Position and momentum of a free electron cannot be determined simultaneously with absolate accuracy .wherreas that of a cricket ball can be determined with almost near certainty |
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| 1432. |
An element has protons whose mass is equal to `23,881`, times that of an electron. Identify the element and write its electronic configuration. |
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Answer» Mass of proton is `1837`- times than that of an electron. Number of protons `=(23,881)/(1837)=13` Atomic number of the element is 13. So, the element is aluminium and its electronic configuration `2,8,3`. |
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| 1433. |
The energy of second orbit of hydrogen is equal to the energy of ,A. fourth orbit of `He^(+)`B. fourth orbit of `Li^(2+)`C. Second orbit of `He^(+)`D. second orbit of `Li^(2+)`. |
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Answer» Correct Answer - A `E=-(Z^(2))/(n^(2))xx13.6eV` `E_(2)=-(13.6)/(4)` for `H` `E=-(Z^(2))/(n^(2))xx13.6` eV `-(13.6)/(4)=-(Z^(2))/(n^(2))xx13.6` `(Z^(2))/(n^(2))=(1)/(4)(Z=1,n=2)`. |
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| 1434. |
The ratio of radii of first orbits of H, `He^(+)` and `Li^(2+)` is:A. `1:2:3`B. `6:3:2`C. `1:4:9`D. `9:4:1` |
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Answer» Correct Answer - B `r=(n^(2))/(Z)xx0.529` Ã… `r_(H):r_(He^(+)):r_(Li^(+2))` `1:(1)/(2):(1)/(3)` `6:3:2` |
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| 1435. |
In an atom two elerctrons move aroundhe nucleus in circulart orbits ro radii ( R) and ( 4 r) . The ratio of the time taken by them to complete one revolution is :A. `1 :4`B. ` 4 :1`C. ` 1: 8`D. `8 :`7 |
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Answer» Correct Answer - C ` T= ( 2 pi r_n)/(u_n) = ( 2 pi _1 xx n^2)/( n_1 //n) ( therefore r_(n) = n^(2)xx r_(1))` or `T prop n^(3)`, `therefore T_(1) /T_(2) = 1_(3)/( n^(3)) = (1)/(8)(n=2)`. |
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| 1436. |
Which of the following is the number of electron present in `X^(2+)` on the basis of electronic configuration if the ion `X^(3-)` has `14` protons ?A. 12B. 14C. 16D. 18 |
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Answer» `X^(3-)` has `14` proton i.e. X also has `14` proton .Therefore `14` electron `X = 14 = 1s^(2) 2s^(2) 2p^(6)3s^(2)3p^(2)` `X^(1+) = 1s^(2) 2s^(2) 2p^(6)3s^(2) = 12` electrons` |
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| 1437. |
Which are will have, a higher velocity to produce matter waves of the same wavelength?A. protonB. neutronC. electronD. None of these |
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Answer» Correct Answer - C `lambda = (h)/(mv)`, being lighter particles, electrons will have higher velocity. |
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| 1438. |
The ratio of radii of first orbits of H, `He^(+)` and `Li^(2+)` is:A. `1 : 2 : 3`B. `6 : 3 : 2`C. `1 : 4 : 9`D. `9 : 4 : 1` |
| Answer» Correct Answer - 2 | |
| 1439. |
The angular momentum of an electron in a hydrogen atom is proportional toA. `(1)/(sqrt(r))`B. `(1)/(r)`C. `r^(2)`D. `sqrt(r)` |
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Answer» Correct Answer - A `KE = (p^(2))/(2r)` `KE prop (1)/(r) p prop (1)/(sqrt(r))` |
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| 1440. |
Whaich of the following statement is /are true ?A. One orbit can accommodate a maximum of two electronB. One sub-shell can acocmmodate a maximum of two electronC. One orbit can accommodate a maximum of two electronD. None of these |
| Answer» An orbital can accommodate a maximum of two electron having opposite spin | |
| 1441. |
Which of the following sub - shells is not permitted ?A. 4fB. 4dC. 3sD. 4g |
| Answer» Correct Answer - 4 | |
| 1442. |
All isotopes of a given element show the same type of chemical behaviour:A. The chemical properties of an atom are controlled by the number of electrons in the atomsB. The chemical properties of an atom are controlled by the number of electrons in the atomC. The chemical properties of an atom are controlled by the numeber of mass in the atomD. none |
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Answer» Correct Answer - A Isotopes have same electronic arrangement |
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| 1443. |
Ratio of frequency of revolution of electron in the second state of `He^(o+)` revolution of electron in the second state `He^(Theta)` and second state of hydrogen isA. `(32)/(27)`B. `(27)/(32)`C. `(1)/(34)`D. `(27)/(2)` |
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Answer» Frequency `v = (v)/(2pi r), v prop (Z)/(n) and r prop n^(2)/(Z)` `rArr v prop (Z^(2))/(n^(2)) ` so `(He^(o+))/(n_(2)^(o+)) = (Z^(2)//3^(2))/(1^(2)//2^(3)) = (8 xx 4)/(27) = (32)/(27)` second excited `rArr n = 3` |
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| 1444. |
Select the one :A. `4f`B. `5d`C. `3sD. `6p` |
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Answer» Correct Answer - C `(n+l)` for rest all is `=7` For 3s it is 3+ 0 =3 . |
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| 1445. |
The angular momentum of an electron due to its spin is given as ………..A. `sqrt(s(s+1))(h)/(2pi)`B. `s(s+1)(h)/(2pi)`C. `(h)/(2pi)`D. `s(s+1)(2pi)/(h)` |
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Answer» Correct Answer - A spin angular momentum `= sqrt(s(s+D)) (h)/(2pi)` |
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| 1446. |
The number of radial nodes, nodal planes for an orbital with `n = 4, 1 = 1` isA. 3,1B. 2,1C. 2,0D. 4,0 |
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Answer» Correct Answer - B No of radial nodes `= n -l - 1` No ofnodal planes = l |
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| 1447. |
Number of nodal centres for 2s orbitalA. 1B. 0C. 4D. 3 |
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Answer» Correct Answer - A Number of nodal centre for 2s orbitals (n-1)=2-1=1 |
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| 1448. |
Which of the d orbitals lies in the xy-plane ?A. `d_(xy)`onlyB. `d_(xz))` onlyC. `d_(z^(2))` onlyD. `d_(xy)and_(z^(2))` |
| Answer» Correct Answer - 1 | |
| 1449. |
Ratio of frequency of revolution of electron in the second state of `He^(o+)` revolution of electron in the second state `He^(Theta)` and second state of hydrogen isA. `(32)/(27)`B. `(27)/(32)`C. `(1)/(54)`D. `(27)/(2)` |
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Answer» Correct Answer - A `f_(n,z) alpha (z^(2))/(n^(3))` |
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| 1450. |
`{:(Column I,Column II),((A)2p"orbital",(p)"Number of spherical nodes =0"),((B)3d"orbital",(q)"Number of nodal plane=0"),((C)2s"orbital",(r)"Orbital angular momentum number =0"),((D)4s"orbital",(s)"Azimuthal quantum number =0"):}` |
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Answer» Correct Answer - A-p; B-p; C-q,r,s; D-p no of radial nodes `= n - l - 1` no of nodal planes = l `L = sqrt(l(l+1)) (h)/(2pi)` |
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