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question_answer1)
Wavelength of radio waves is
A)
< microwaves done
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B)
> microwaves done
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C)
\[\le \]infrared waves done
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D)
\[\le \]UV rays done
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question_answer2)
Which statement is true?
A)
Spacing between energy levels n =1 and n = 2 in hydrogen atom is greater than that of n=2 and n = 3 done
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B)
Spacing between energy levels n = 1 and n = 2 in hydrogen atom is equal to that n = 2 and n = 3 done
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C)
Spacing between energy levels n = 1 and n =3 in hydrogen atom is less than that of n=2 and n = 3 done
clear
D)
None done
clear
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question_answer3)
Which transition in \[L{{i}^{{{2}^{+}}}}\] would have the same wavelength as the \[2\text{ }\to \text{ }4\] transition in \[H{{e}^{+}}\] ion?
A)
4 \[\to \] 2 done
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B)
2 \[\to \] 4 done
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C)
3 \[\to \] 6 done
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D)
6 \[\to \] 2 done
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question_answer4)
The electrons, identified by quantum numbers \[n\] and \[l\] (i) n = 4, \[l\]= 1, (ii) n = 4, \[l\]= 0, (iii) n = 3, \[l\]= 2, and (iv) n =3, \[l\] = 1 can be placed in order of increasing energy, from the lowest to highest, as
A)
(iv) < (ii) < (iii) < (i) done
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B)
(ii) < (iv) < (i) < (iii) done
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C)
(i) < (iii) < (ii) < (iv) done
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D)
(iii) < (i) < (iv) < (ii) done
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question_answer5)
Identify the incorrect statements
A)
An electronic wave function must be symmetrical with respect to the interchange of any two electrons done
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B)
\[{{\psi }^{2}}\]must remain unchanged when the spin and space coordinates of the paired electrons are interchanged done
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C)
For an n electron system the wave function \[\psi \] will be a function of 3 n spatial coordinate done
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D)
Antisymmetrical wave function are found to represent the properties of electron. done
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question_answer6)
Uncertainty in position of a minute particle of mass 25 g in space is \[{{10}^{-5}}^{{}}\] m. The uncertainty in its velocity (in m/s) is
A)
\[2.1\times {{10}^{-34}}\] done
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B)
\[0.5\times {{10}^{-34}}\] done
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C)
\[2.1\times {{10}^{-28}}\] done
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D)
\[0.5\times {{10}^{-23}}\] done
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question_answer7)
In Bohr series of lines of hydrogen spectrum, third line from the red end corresponds to which one of the following inner orbit jumps of electron for Bohr's orbit in atom of hydrogen
A)
4 \[\to \] 1 done
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B)
2 \[\to \] 5 done
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C)
3 \[\to \] 2 done
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D)
5 \[\to \] 2 done
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question_answer8)
In a multielectron atom, which of the following orbitals described by the three quantum numbers will have the same energy in the absence of magnetic field
(i) n = l,\[l\]= 0, m=0 |
(ii) n = 2,\[l\]= 0, m =0 |
(iii) n = 2,\[l\]= l ,m = l |
(iv) n = 3,\[l\]= 2, m = l |
(v) n = 3,\[l\]= 2, m = 0 |
A)
(i) and (ii) done
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B)
(ii) and (iii) done
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C)
(iii) and (iv) done
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D)
(iv) and (v) done
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question_answer9)
The "spin-only" magnetic moment [in units of Bohr magnet on, (\[{{\mu }_{B}}\])] of \[N{{i}^{{{2}^{+}}}}\] in aqueous solution would be: (At. no. Ni = 28)
A)
1.73 done
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B)
2.84 done
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C)
4.90 done
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D)
0 done
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question_answer10)
1In an atom, an electron is moving with a speed of 600 m/s with an accuracy of 0.005 %. Certainty with which the position of the electron can be located is (h = 6.6 x \[{{10}^{-34}}\] kg \[{{m}^{2}}\]/s, mass of electron, \[{{e}_{m}}\] = 9.1 x \[{{10}^{31}}\] kg)
A)
\[1.52\times {{10}^{-4}}m\] done
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B)
\[5.10\times {{10}^{-3}}m\] done
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C)
\[1.92\times {{10}^{-3}}m\] done
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D)
\[3.84\times {{10}^{-3}}m\] done
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question_answer11)
The energy required to break 1 mol of \[Cl-Cl\] bonds in \[C{{l}_{2}}\] is 242 kJ/mol. The longest wavelength of light capable of breaking a single \[Cl-Cl\] bond is
A)
594 nm done
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B)
640 nm done
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C)
700 nm done
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D)
494 nm done
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question_answer12)
What are the values of the orbital angular momentum of an electron in the orbitals Is, 3s, 3d and 2p?
A)
\[0,\,0,\,\frac{h}{2\pi }\sqrt{6},\frac{h}{2\pi }\sqrt{2}\] done
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B)
\[1,\,1,\,\frac{h}{2\pi }\sqrt{4},\frac{h}{2\pi }\sqrt{2}\] done
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C)
\[0,\,1,\,\frac{h}{2\pi }\sqrt{4},\frac{h}{2\pi }\sqrt{3}\] done
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D)
\[0,\,0,\,\frac{h}{2\pi }\sqrt{20},\frac{h}{2\pi }\sqrt{6}\] done
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question_answer13)
The wave number of the first line of Balmer series of hydrogen is 15200\[c{{m}^{-1}}\]. The wave number of the corresponding 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
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question_answer14)
The energy of electron in first Bohr's orbit of H-atom is -13.6 eV. What will be its potential energy in n = \[{{4}^{th}}\] orbit
A)
-13.6eV done
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B)
-3.4eV done
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C)
-0.85eV done
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D)
-1.70eV done
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question_answer15)
The MRI (magnetic resonance imaging) body scanners used in hospitals operate with 400 MHz radio frequency The wavelength corresponding to this radio frequency is
A)
0.75 m done
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B)
0.75 cm done
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C)
1.5m done
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D)
2cm done
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question_answer16)
Which of the following statements about quantum numbers is wrong:
A)
If the value of\[l=0\], the electron distribution is spherical done
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B)
The shape of the orbital is given by subsidiary quantuir number. done
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C)
The Zeeman's effect is explained by magnetic quanturr number. done
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D)
The spin quantum number gives the orientations of electron cloud. done
clear
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question_answer17)
A certain metal when irradiated to light (v = 3.2 \[\times {{10}^{16}}\]Hz) emits photoelectrons with twice kinetic energy as did photoelectrons when the same metal is irradiated by ligh1 (v = 2.0 \[\times {{10}^{16}}\] Hz) The \[{{v}_{0}}\] (threshold frequency) of metal is
A)
\[1.2\times {{10}^{14}}Hz\] done
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B)
\[8\times {{10}^{15}}Hz\] done
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C)
\[1.2\times {{10}^{16}}Hz\] done
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D)
\[4\times {{10}^{12}}Hz\] done
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question_answer18)
The ratio of the radii of the three Bohr orbits is
A)
1:1/2:1/3 done
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B)
1:2:3 done
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C)
1:4:9 done
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D)
1:8:27 done
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question_answer19)
A photon of frequency n causes photoelectric emission from a surface with threshold frequency \[{{n}_{0}}\].The de Broglie wavelength\[\lambda \]of the photoelectron emitted is given as
A)
\[\Delta n=\frac{h}{2m\lambda }\] done
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B)
\[\Delta n=\frac{h}{\lambda }\] done
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C)
\[\left[ \frac{1}{{{v}_{0}}}-\frac{1}{v} \right]=\frac{m{{c}^{2}}}{h}\] done
clear
D)
\[\lambda =\sqrt{\frac{h}{2m\Delta n}}\] done
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question_answer20)
The total spin and magnetic moment for the atom with atomic number 7 are:
A)
\[\pm 3,\,\sqrt{3}BM\] done
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B)
\[\pm 1,\,\sqrt{8}BM\] done
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C)
\[\pm \frac{3}{2},\,\sqrt{15}BM\] done
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D)
\[0,\sqrt{8}BM\] done
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question_answer21)
The maximum number of electrons can have principal quantum number n = 3 and spin quantum number \[{{M}_{S}}\] = -1/2 is
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question_answer22)
The work function (\[\phi \]) of some metals is listed below. The number of metals which will show photoelectric effect when light of 300 nm wavelength falls on the metal is Metal Li Na K Mg Cu Ag Fe Pt W \[\phi \](eV) 2.4 2.3 2.2 3.7 4.8 4.3 4.7 6.3 4.75
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question_answer23)
The atomic masses of He and Ne are 4 and 20 a.m.u., respectively. The value of the de Broglie wavelength of He gas at \[-73{}^\circ C\] is "M" times that of the de Broglie wavelength of Ne at \[727{}^\circ C\]. M is
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question_answer24)
The \[\lambda \] of \[{{H}_{a}}\] line of the Balmer series is \[6500\text{ }\overset{\text{o}}{\mathop{\text{A}}}\,\]. What is the\[\lambda \]of \[{{H}_{\beta }}\] line of the Balmer series?
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question_answer25)
The wavelength of the radiations emitted in nm when in a hydrogen atom electron falls from infinity to stationary state is (\[{{R}_{H}}=1.097\times {{10}^{7}}{{m}^{-1}}\]):
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