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question_answer1)
The ionization energy of hydrogen atom (in the ground state) is x kJ. The energy required for an electron to jump from 2nd orbit to the \[{{3}^{rd}}\] orbit will be
A)
x/6 done
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B)
5x done
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C)
7.2 x done
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D)
5x/36 done
clear
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question_answer2)
The magnetic moment of a transition metal ion is found to be 5.92 BM. The number of unpaired electrons present in it is
A)
2 done
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B)
3 done
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C)
4 done
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D)
5 done
clear
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question_answer3)
Let \[{{v}_{1}}\] be the frequency of the series limit of the Lyman series, \[{{v}_{2}}\] be the frequency of the first line of the Lyman series, and \[{{v}_{3}}\] be the frequency of the series limit of the Balmer series, then
A)
\[{{v}_{3}}=\frac{1}{2}({{v}_{1}}-{{v}_{3}})\] done
clear
B)
\[{{v}_{2}}-{{v}_{1}}={{v}_{3}}\] done
clear
C)
\[{{v}_{1}}-{{v}_{2}}={{v}_{3}}\] done
clear
D)
\[{{v}_{1}}+{{v}_{2}}={{v}_{3}}\] done
clear
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question_answer4)
Arrange the following particles in increasing order of values of e/m ratio : electron (e), proton (p), neutron (n) and \[\alpha -\]particle \[(\alpha )\]
A)
\[n,\,p,\,e,\,\alpha \] done
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B)
\[n,\,\alpha ,\,p,\,e\] done
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C)
\[n,\,p,\,\alpha ,\,e\] done
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D)
\[e,\,p,\,n,\,\alpha \] done
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question_answer5)
Naturally occurring boron consists of two isotopes whose atomic weights are 10.01 and 11.01. The atomic weight of natural boron is 10.81. Calculate the percentage of each isotope in natural boron.
A)
20, 80 done
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B)
30, 70 done
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C)
10, 90 done
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D)
15, 85 done
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question_answer6)
Magnetic moments of \[Cr(Z=24),\,Mn(Z=25)\] and \[Fe(Z=26)\] are \[x,\,y\] and \[z\] respectively. Hence,
A)
\[x=y=z\] done
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B)
\[x=y<z\] done
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C)
\[x<y<z\] done
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D)
\[x>y>z\] done
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question_answer7)
Last line of Lyman series for H-atom has wavelength \[{{\lambda }_{1}}\overset{o}{\mathop{A}}\,,\] \[{{2}^{nd}}\] line of Balmer series has wavelength \[{{\lambda }_{2}}\overset{o}{\mathop{A}}\,\] then
A)
\[\frac{16}{{{\lambda }_{1}}}=\frac{9}{{{\lambda }_{2}}}\] done
clear
B)
\[\frac{16}{{{\lambda }_{2}}}=\frac{9}{{{\lambda }_{1}}}\] done
clear
C)
\[\frac{4}{{{\lambda }_{1}}}=\frac{1}{{{\lambda }_{2}}}\] done
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D)
\[\frac{16}{{{\lambda }_{1}}}=\frac{3}{{{\lambda }_{2}}}\] done
clear
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question_answer8)
| Photon having wavelength 310 nm is used to break the bond of \[{{A}_{2}}\] molecule having bond energy \[288\,kg\,mo{{l}^{-1}}\] then % of energy of photon converted to the K.E. is |
| \[[hc=12400\,ev\,\overset{o}{\mathop{A}}\,,\,1\,ev=96\,kJ/mol]\] |
A)
25 done
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B)
50 done
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C)
75 done
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D)
80 done
clear
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question_answer9)
Table-tennis ball has a mass 10 g and a speed of 90 m/s. If speed can be measured within an accuracy of 4% what will be the uncertainity in speed and position
A)
\[1.58\times {{10}^{-34}}\,m\] done
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B)
\[1.46\times {{10}^{-33}}\,m\] done
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C)
\[2.45\times {{10}^{-24}}\,m\] done
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D)
\[3.48\times {{10}^{-31}}\,m\] done
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question_answer10)
Which of the following sets of quantum numbers is not permitted?
A)
\[n=3,\,l=3,\,m=0,\,s=+1/2\] done
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B)
\[n=3,\,l=2,\,m=+2,\,s=-1/2\] done
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C)
\[n=3,\,l=1,\,m=-2,\,s=-1/2\] done
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D)
\[n=3,\,l=0,\,m=0,\,s=+1/2\] done
clear
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question_answer11)
Photoelectric emission is observed from a surface for frequencies \[{{v}_{1}}\] and \[{{v}_{2}}\] of the incident radiation\[({{v}_{1}}-{{v}_{2}})\]. If the maximum kinetic energies of the photoelectrons in the two cases are in the ratio 1: k then the threshold frequency \[{{v}_{1}}\] is given by
A)
\[\frac{{{v}_{2}}-{{v}_{1}}}{k-1}\] done
clear
B)
\[\frac{k{{v}_{1}}-{{v}_{2}}}{k-1}\] done
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C)
\[\frac{k{{v}_{2}}-{{v}_{1}}}{k-1}\] done
clear
D)
\[\frac{{{v}_{2}}-{{v}_{1}}}{k}\] done
clear
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question_answer12)
The wave number of first line of Balmer series of hydrogen is \[15200\,c{{m}^{-1}}\]. The wave number of first Balmer line of \[L{{i}^{2+}}\] ion is
A)
\[15200\,c{{m}^{-1}}\] done
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B)
\[60800\,c{{m}^{-1}}\] done
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C)
\[76000\,c{{m}^{-1}}\] done
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D)
\[136800\,c{{m}^{-1}}\] done
clear
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question_answer13)
In which of the following Aufbau principle and Hund's rule is violated?
A)
B)
C)
D)
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question_answer14)
What is the maximum number of electrons in an atom that can have quantum numbers \[n=4\,{{m}_{e}}=+1\]
A)
4 done
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B)
15 done
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C)
3 done
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D)
6 done
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question_answer15)
Average atomic mass of magnesium is 24.32 amu. This Mg is composed of 79 mole % of \[^{24}Mg\] and remaining 21 mole % of \[^{25}Mg\] and \[^{26}Mg\]. Calculate the mole % of \[^{25}Mg\]
A)
10% done
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B)
20% done
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C)
22% done
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D)
11% done
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question_answer16)
Wave function of an orbital is given below in the variation or w.r.t. distance from nucleus. It may the graphical representation of
A)
1s done
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B)
2s done
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C)
2p done
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D)
3s done
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question_answer17)
If the diameter of two different nuclei are in the ratio 1 : 3 then their mass number are in the ratio :
A)
1 : 3 done
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B)
1 : 9 done
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C)
27 : 1 done
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D)
1 : 27 done
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question_answer18)
An electron in an atom jumps in such a way that its kinetic energy changes from \[x\] to \[x/4\]. The change in potential energy will be:
A)
\[+\frac{3}{2}x\] done
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B)
\[-\frac{3}{8}x\] done
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C)
\[+\frac{3}{4}x\] done
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D)
\[-\frac{3}{4}x\] done
clear
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question_answer19)
The angular momentum of an electron in a given orbit is J. Its kinetic energy will be:
A)
\[\frac{1}{2}\,\frac{{{J}^{2}}}{m{{r}^{2}}}\] done
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B)
\[\frac{Jv}{r}\] done
clear
C)
\[\frac{{{J}^{2}}}{2m}\] done
clear
D)
\[\frac{{{J}^{2}}}{2\,\pi }\] done
clear
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question_answer20)
If in Bohr's model, for unielectronic atom, time period of revolution is represented as \[{{T}_{\,n,Z}}\] where n represents shell no. and Z represents atomic number then the value of \[{{T}_{1,\,2}}:{{T}_{2,\,1}}\] will be:
A)
8 : 1 done
clear
B)
1 : 8 done
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C)
1 : 1 done
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D)
1 : 32 done
clear
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question_answer21)
A hydrogen atom in the ground state is excited by monochromatic radiation of wavelength \[\lambda \overset{o}{\mathop{A}}\,\]. The resulting spectrum consists of maximum 15 different lines. What is the wavelength \[\lambda \]?
A)
\[937.3\,\overset{o}{\mathop{A}}\,\] done
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B)
\[1025\,\overset{o}{\mathop{A}}\,\] done
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C)
\[1236\,\overset{o}{\mathop{A}}\,\] done
clear
D)
None of these done
clear
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question_answer22)
From the following list of atoms, choose the no. of pairs of isotopes, isobars and isotones respectively \[_{8}^{16}O,\,_{19}^{39}K,\,_{19}^{335}U,\,_{19}^{40}K,\,_{7}^{14}N,\,_{8}^{18}O,\,_{6}^{14}C,\,_{20}^{40}Ca,\,_{92}^{238}U\]
A)
3, 2, 2 done
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B)
2, 3, 2 done
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C)
2, 2, 3 done
clear
D)
2, 2, 2 done
clear
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question_answer23)
Which of the following sets of quantum numbers represent the highest stability of an atom?
A)
\[n=4,\,\ell =1,\,m=0,\,s=+1/2\] done
clear
B)
\[n=4,\,\ell =0,\,m=0,\,s=+1/2\] done
clear
C)
\[n=4,\,\ell =2,\,m=1,\,s=+1/2\] done
clear
D)
\[n=3,\,\ell =1,\,m=0,\,s=+1/2\] done
clear
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question_answer24)
For a hypothetical hydrogen like atom, the potential energy of the system is given by \[U(r)=\frac{-k{{e}^{2}}}{{{r}^{4}}}\] where r is the distance between the two particles. If Bohr's model of quantization of angular momentum is applicable, then velocity of particle is given by
A)
\[\frac{nh}{16\,ke{{\pi }^{2}}\,{{m}^{3/2}}}\] done
clear
B)
\[\frac{{{n}^{2}}{{h}^{2}}}{18\,{{k}^{2}}{{e}^{2}}{{\pi }^{2}}\,{{m}^{3}}}\] done
clear
C)
\[\frac{{{n}^{3}}{{h}^{3}}}{18\,{{k}^{2}}{{e}^{2}}{{\pi }^{3}}\,{{m}^{4}}}\] done
clear
D)
\[\frac{{{n}^{2}}{{h}^{2}}}{4\sqrt{2}\,ke{{\pi }^{2}}{{m}^{3/2}}}\] done
clear
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question_answer25)
Which of the following about wave function \[\psi \] is not correct?
A)
\[\psi \] may be a real valued wave function done
clear
B)
\[\psi \] may be in some cases be a complex function done
clear
C)
\[\psi \] has a mathematical significance only done
clear
D)
\[\psi \] is proportional to the probability of finding an electron done
clear
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question_answer26)
The orbital angular momentum for an electron revolving in an orbit is given by \[\sqrt{l(l+1)}\frac{h}{2\pi }\]. This momentum for \[{{d}^{5}},\,{{d}^{6}},\,{{p}^{3}}\] electron will be respectively
A)
\[\sqrt{6}\,\frac{h}{2\pi },\,\sqrt{7}\,\frac{h}{2\pi },\,\sqrt{2}\,\frac{h}{2\pi }\] done
clear
B)
\[0\,\frac{\sqrt{6}h}{2\pi },\,\frac{\sqrt{2}h}{2\pi }\] done
clear
C)
\[\sqrt{6}\,\frac{h}{2\pi },\,\sqrt{6}\frac{6}{2\pi },\,\sqrt{2}\frac{h}{2\pi }\] done
clear
D)
\[\sqrt{6}\,\frac{h}{2\pi },\,\sqrt{6}\frac{h}{2\pi },\,\sqrt{3}\frac{h}{2\pi }\] done
clear
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question_answer27)
An electron, a proton and an alpha particle have kinetic energies of 16E, 4E and E respectively. What is the qualitative order of their de-Broglie wavelengths?
A)
\[{{\lambda }_{e}}>{{\lambda }_{p}}={{\lambda }_{\alpha }}\] done
clear
B)
\[{{\lambda }_{p}}={{\lambda }_{\alpha }}={{\lambda }_{e}}\] done
clear
C)
\[{{\lambda }_{p}}>{{\lambda }_{e}}>{{\lambda }_{\alpha }}\] done
clear
D)
\[{{\lambda }_{\alpha }}<{{\lambda }_{e}}>{{\lambda }_{p}}\] done
clear
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question_answer28)
In a sample of H-atom electrons make transition from 5th excited state to ground state, producing all possible types of photons, then number of lines in infrared, region are
A)
4 done
clear
B)
5 done
clear
C)
6 done
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D)
3 done
clear
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question_answer29)
Number of electrons having \[\ell +m\] value equal to zero in \[_{26}Fe\] may be
A)
13 done
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B)
20 done
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C)
7 done
clear
D)
12 done
clear
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question_answer30)
| The following transition occurs when Lithium atoms are sprayed into hot flame. The various steps are numbered for identification. |
| \[2s\xrightarrow{I}2p\xrightarrow{II}3d\xrightarrow{III}3p\xrightarrow{IV}\]\[4s\xrightarrow{V}3p\] |
| Which of these transitions result in emission of light? |
A)
I, II & V done
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B)
III & V done
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C)
III, IV & V done
clear
D)
All done
clear
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question_answer31)
Match List-I with List-II and select the correct answer using the code given below the lists:
| List-I |
List-I |
| Sub-atomic particles |
Persons responsible for discovery |
| (A) Electron |
(p) James Chadwick |
| (B) Proton |
(q) J.J. Thomson |
| (C) Neutron |
(r) Rutherford |
| (D) Nucleus |
(s) Goldstein |
Codes:
A)
A\[\to \]q, B\[\to \]s, C\[\to \]r, D\[\to \]p done
clear
B)
A\[\to \]p, B\[\to \]p, C\[\to \]q, D\[\to \]s done
clear
C)
A\[\to \]r, B\[\to \]s, C\[\to \]p, D\[\to \]q done
clear
D)
A\[\to \]q, B\[\to \]s, C\[\to \]p, D\[\to \]r done
clear
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question_answer32)
Number of electron having the quantum numbers \[n=4,\,\ell =0,\,s=-\frac{1}{2}\] in \[Z{{n}^{+2}}\] ion is/are:
A)
1 done
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B)
0 done
clear
C)
2 done
clear
D)
5 done
clear
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question_answer33)
What is the total spin value in case of \[_{26}F{{e}^{3+}}\] ion?
A)
+ 1 or - 1 done
clear
B)
+ 2 or - 2 done
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C)
+ 2.5 or - 2.5 done
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D)
+ 3 or - 3 done
clear
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question_answer34)
\[{{\psi }^{2}}=0\] represent
A)
node done
clear
B)
orbital done
clear
C)
zero amplitude of wave done
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D)
wave function done
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question_answer35)
Correct set of four quantum numbers for the outermost electron of rubidium (Z = 37) is -
A)
5, 0, 0, 1/2 done
clear
B)
5, 1, 0, 1/2 done
clear
C)
5, 1, 1, 1/2 done
clear
D)
6, 0, 0, 1/2 done
clear
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done
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done
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done
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done
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