Q.1.
The quantum number +1/2 and -1/2 for the electron spin represent ... [ IIT 2001]
-
75%
a)rotation of the electron in clockwise and anticlockwise direction respectively
-
12%
b) rotation of the electron in anticlockwise and clockwise direction respectively
-
12%
c)magnetic moment of the electron pointing up and down respectively
-
0%
d)two quantum mechanical spin states which have no classical analogues
Explanation
Q.2.
The mass of one mole of electron is
-
33%
a) 9.1 × 10-28 g
-
17%
b) 0.55 mg
-
33%
c)9.1 × 10-24 g
-
17%
d)1.005 mg
Q.3.
the ratio of ionization energy of H and Be+3 is ...{pb CET 1996]
-
17%
a)1:1
-
33%
b)1:3
-
33%
c)1:9
-
17%
d)1:16
Q.4.
A 200 g cricket ball is thrown with a speed 3×103 cm/sec, what will be its de Broglie wavelength? [ Pb. CET 1986]
-
25%
a) 1.1 ×10-32 cm
-
0%
b) 2.2 ×10-32 cm
-
25%
c) 0.55 × 10-32 cm
-
50%
d) 11.0 × 10-32 cm
Explanation
Q.5.
In Cu ( At. No 29) [Haryana CEET 2000]
-
20%
a)13 electrons have spin in one direction and 16 electrons in other direction
-
60%
b) 14 electrons have spin one direction and 15 electrons in other direction
-
20%
c)one electron can have spin only in the clockwise direction
-
0%
d)none of the above is correct
Explanation
Q.6.
The energy of a photon is given as ΔE/atom=3.03×10-19 J atom-thus the wavelength (λ) of photon is .. [CBSE PMT 2000]h=6.63 ×10-34 Js, c=3.0 ×108 m/s
-
20%
a) 65.5 nm
-
60%
b) 656 nm
-
0%
c)0.656 nm
-
20%
d)6.56 nm
Q.7.
In hydrogen atom, energy of first excited state is -3.4eV. then find out the Kinetic energy of the same orbit of hydrogen atom [ CBSE PMT 2002]
-
50%
a) +3.4 eV
-
38%
b) +6.8 eV
-
12%
c)-13.6 eV
-
0%
d)+13.6 eV
Explanation
Q.8.
t 200°C, the velocity of hydrogen molecule is 2.0×105 cm/sec. In this case the de Broglie wavelength is about... [ CBSE PMT 1990]
-
57%
a) 1 Ao
-
43%
b) 1000 Ao
-
0%
c) 100 Ao
-
0%
d) 10 Ao
Q.9.
In the ground state, an element has 13 electrons in its M-shell. The element is ... [ EAMCET 2001]
-
20%
a)Cobalt
-
40%
b) Chromium
-
40%
c)Nickel
-
0%
d)Iron
Explanation
Q.10.
If the nitrogen atom had electron configuration 1s7, it will would have energy lower than that of the normal ground state configuration 1s2 2s2 2p3 because the electrons would be closer to the nucleus. Yet 1s7 is not observed. It violets ... [ IIT 2002]
-
20%
a) Heisenberg's uncertainty principle
-
40%
b) Hund's rule
-
20%
c)Pauli's exclusion principle
-
20%
d)Bohr postulate of stationary orbits
Q.11.
The energy of hydrogen atom in ground state is -13.6 eV. the energy of the level corresponding to the quantum number n=5 is ...[ CBSE PMT 1990]
-
25%
a) -0.54 eV
-
25%
b) -5.40 eV
-
50%
c)-0.85 eV
-
0%
d)-2.72 eV
Q.12.
The kinetic energy of an electron accelerated from rest through a potential difference of 5V will be ... [ Kerals CEE 2001]
-
40%
a) 5 J
-
20%
b) 5 erg
-
20%
c) 5 eV
-
20%
d) 80 eV
Q.13.
Among the following groupings which represents the collection of isoelectronic species?... [ CBSE PMT 2000]
-
0%
a)NO+, C22- O2-, CO
-
0%
b) N2, C22-, CO, NO
-
100%
c)CO, NO+, CN-, C22-
-
0%
d)NO, CN-, N2, O2-
Q.14.
As the nuclear change increases from Neon to calcium, the orbitals energies ... [ kerala MEE]
-
25%
a)increases
-
0%
b)increases very rapidly
-
75%
c)increases very slowly
-
0%
d)fall
Q.15.
Ratio of energy of photon of wavelength 3000Å and 6000Å is ... [AFMC 1999]
-
25%
a) 3 :1
-
25%
b) 2 :1
-
25%
c)1:2
-
25%
d)1:3
Q.16.
the Bohr orbit radius for H-atom ( Z=1) ia approximately 0.53Å. the radius for the first excited state orbit is ...[ CBSE PMT 1998]
-
33%
a) 0.13 Å
-
0%
b) 1.06 Å
-
33%
c) 4.77 Å
-
33%
d) 2.12 Å
Q.17.
For how many orbitals, the quantum number n=3, l=2, m=+2 are possible? [ CBSE Med. 2001]
-
0%
a)1
-
25%
b) 2
-
25%
c)3
-
50%
d)4
Q.18.
Rutherford's experiment which established the nuclear model of the atom used a beam of .... [IIT 2002]
-
0%
a) β particles which impinged on metallic foil and got absorbed
-
40%
b) γ -ray which impinged on a metal foil and ejected electrons
-
20%
c)helium atoms, which impinged on a metal foil and got scattered
-
40%
d)helium nuclei, which impinged on a metal foil and got scattered
Q.19.
What transition in the hydrogen spectrum would have the same wavelength as the Balmer transition n=4 to n=2 in the He+ spectrum [ IIT 1993]
-
50%
a)n=4 to n=1
-
17%
b) n=3 to n=2
-
33%
c)n=3 to n=1
-
0%
d)n=2 to n=1
Q.20.
Light of wavelength λ shines on a metal surface with intensity x and the metal emits y electrons per second of average energy z. What will happen to y and Z if x is doubled.
-
40%
a) y will be doubled but z will remain same
-
20%
b) both y and z will be doubled
-
20%
c) y will remain same and z will be doubled
-
20%
d) y will be doubled and z will become half
Q.21.
A 5d orbital has ... [ Kerala MEE 2000]
-
0%
a)one node
-
43%
b) two nodes
-
0%
c)three nodes
-
57%
d)four nodes
Q.22.
An element M has an atomic mass 19 and atomic numberIts ion is represented by ... [ manipal PMT 2001]
-
0%
a) M+
-
25%
b) M2+
-
50%
c)M-
-
25%
d)M2-
Q.23.
The radius of hydrogen atom in the ground state is 0.53Å. the radius of Li2+ ion ( atomic number 3 ) in similar state is ...[ CBSE PMT 1995]
-
50%
a) 0.17 Ao
-
0%
b) 1.06 Ao
-
25%
c) 0.53Ao
-
25%
d) 0.265Ao
Explanation
Q.24.
The uncertainty in the position of an electron ( mass 9.1×10-28 g) moving with velocity of 3.0×104 cm s-1 accurate up to 0.11% will be ... [ CBSE PMT 1995]
-
43%
a)1.92 cm
-
14%
b) 7.68 cm
-
0%
c)0.175 cm
-
43%
d)3.84 cm
Explanation
Q.25.
The number of photons of light having wave number x in 1J of energy source is ...
-
12%
a) hcx
-
38%
b) hc/x
-
38%
c)x/hc
-
12%
d)1/hcx
Explanation
Q.26.
Number of nodel planes in px orbital is [ IIT 2000]
-
40%
a) one
-
20%
b) two
-
20%
c)three
-
20%
d)zero
Q.27.
the polarizing ability of which one of the following is highest? [ DEC 2003]
-
50%
a) large -ve ion
-
17%
b) small, highly -ve ion
-
17%
c) large +ve ion
-
17%
d) small, highly +ve ion
Q.28.
Which of the following molecules has pyramidal shape ? [ DEC 2004]
-
75%
a)CO2-
-
25%
b) SPO3
-
0%
c)PCl3
-
0%
d)NO3-
Q.29.
Assertion : The radius of second orbit of He+ is equal to that of first orbit of hydrogen. Reason : The radius of an orbit in hydrogen like species is directly proportional to n and inversely proportional to Z.
-
60%
a) Both Assertion and Reasoning are true and Reasoning is correct explanation of Assertion
-
20%
b) Both are correct but Reason is not explanation of Assertion
-
0%
c) Assertion is correct but Reason is wrong
-
20%
d) Both Assertion and Reason are incorrect.
Q.30.
The orbital angular momentum for an electron revolving in an 's' orbit is given by .. [ AIEEE 2003]
-
0%
a)h/4π
-
50%
b) zero
-
25%
c)h/2π
-
25%
d)h/(√2π)
Q.31.
uggest two transitions in the atomic spectrum hydrogen for which the wave number ratio is 108 :7
-
20%
a) First Lyman and first Bracket transition
-
20%
b) First and second Lyman series transition
-
40%
c) First Lyman and first Balmer transition
-
20%
d) First Lyman and first Paschen transition
Q.32.
The threshold energy is given as E0 and radiation of energy E falls on metal, then K.E. is given as
-
25%
a) (E- E0)/2
-
25%
b) E- E0
-
50%
c) E0 - E
-
0%
d) E/E0
Explanation
Q.33.
Which of the following is not linear molecule? [DEC 2003]
-
0%
a) BeCl2
-
0%
b) CS2
-
75%
c)CO2
-
25%
d)SO3
Q.34.
Correct energy value order is ... [ Orisa JEE 2004]
-
23%
a) ns, np, nd, (n-1)f
-
31%
b) ns, np, (n-1)d, (n-2)f
-
31%
c)ns, np, (n-1)d, (n-1)f
-
15%
d)ns, (n-1)d, np, (n-2)f
Q.35.
the position of both, electron and helium atom is known with in 0.1nm. Further the momentum of electron is known with in 5.0×10-26 kg ms-1The minimum uncertainty in the measurement of momentum of helium atom is
-
17%
a) 50 kg m s-1
-
67%
b) 5.0 ×10-26 kg m s-1
-
0%
c) 80 kg m s-1
-
17%
d) 80.0 ×10-26 kg m s-1
Q.36.
The number of waves in the third orbit of H atom is
-
0%
a) 1
-
40%
b) 2
-
20%
c) 3
-
40%
d) 4
Q.37.
The ionization energy of the electron in the lowest orbit of hydrogen atom is 13.6 eV. The energies required in eV to remove electron from three lowest orbits of hydrogen atom are
-
17%
a) 13.6, 6.8, 8.4
-
50%
b) 13.6, 10.2, 3.4
-
17%
c) 13.6, 27.2, 40.8
-
17%
d) 13.6, 3.4, 1.51
Explanation
Q.38.
Any f-orbital can accommodate upto
-
0%
a) 2 electrons with parallel spin
-
0%
b) 6 electrons
-
25%
c) 2 electrons with opposite spin
-
75%
d) 14 electrons
Explanation
Q.39.
Probability can be assessed by
-
33%
a) ψ2
-
17%
b) ψψ*
-
33%
c) both above
-
17%
d)ψ*
Q.40.
The correct order of increasing energy of atomic orbital is
-
25%
a) 5p < 4f < 6s < 5d
-
50%
b) 5p < 6s < 4f < 5d
-
0%
c) 4f < 5p < 5d < 6s
-
25%
d) 5p < 5d < 4f < 6s
Q.41.
Assertion : Wavelength for first line of any series in hydrogen spectrum is biggest among all other lines of the same series. Reason : Wavelength of spectral line for an electronic transition is inversely related to difference in the energy levels involved in the transition.
-
60%
a) Both Assertion and Reasoning are true and Reasoning is correct explanation of Assertion
-
20%
b) Both are correct but Reason is not explanation of Assertion
-
0%
c) Assertion is correct but Reason is wrong
-
20%
d) Both Assertion and Reason are incorrect.
Q.42.
Consider the following statements,. the d-orbitals have(i) four lobes and two nodes(ii) four lobes and one node(iii)same sign in opposite lobs(iv)opposite sign in the opposite lobs
-
0%
a)1 alone
-
50%
b) 1 and 3
-
25%
c)2 and 3
-
25%
d)1 and 4
Q.43.
If r1 is the radius of the first orbit of hydrogen atom, then the radii of second, third and fourth orbitals in terms of r1 are
-
0%
a) r12, r13 , r14
-
25%
b) 8r1, 27r1, 64r1
-
50%
c) 4r1, 9r1, 16r1
-
25%
d) 2r1, 6r1, 8r1
Q.44.
For a particle it is found that uncertainty in velocity (in ms-1) is reciprocal of the uncertainty in position (in m). the mass of the particle will have
-
25%
a)a fixed value
-
25%
b) a variable value
-
25%
c)a value not grater than a particular value
-
25%
d)a value not less than a particular value
Q.45.
The radius of hydrogen atom in the ground state is 0.53 Å. The radius of Li2+ ion (atomic number = 3) in a similar state is
-
75%
a) 0.53 Å
-
0%
b) 1.06 Å
-
0%
c) 0.16 Å
-
25%
d) 0.265 Å
Q.46.
the maximum number of electrons in a subshell having the same value of spin quantum number is given by
-
0%
a) l+2
-
40%
b) 2l+1
-
40%
c)l(l+1)
-
20%
d)√[l(l+1)]
Explanation
Q.47.
Which of the following statement is false?
-
0%
a) The optical microscope makes use of the wave property of light, while the electron microscope uses the particle property of electrons
-
25%
b) Raman spectrometer uses the wave property of light, while the electron microscope uses the wave property of electrons
-
25%
c) Optical microscope uses the wave property of light, electron microscope uses the wave property of electrons
-
50%
d) Optical microscope uses the wave property of light, while Raman spectrometer uses the particle property of light
Q.48.
The energies of orbitals of H-atom are in the order
-
25%
a) 3s < 3p < 4s < 3d < 4p
-
0%
b) 3s < 3p < 3d < 4s < 4p
-
50%
c) 3s = 3p = 3d < 4s = 4p
-
25%
d) 3s = 3p = 3d < 4s < 4p
Q.49.
Assertion : Bohr’s orbits are also called stationary states. Reason : Electrons are stationary in an orbit.
-
67%
a) Both Assertion and Reasoning are true and Reasoning is correct explanation of Assertion
-
0%
b) Both are correct but Reason is not explanation of Assertion
-
0%
c) Assertion is correct but Reason is wrong
-
33%
d) Both Assertion and Reason are incorrect.
Q.50.
For a particles having same kinetic energy, the deBroglie wavelength is
-
0%
a)directly proportional to its velocity
-
40%
b) inversely proportional to its velocity
-
20%
c)independent of velocity and mass
-
40%
d)meaningless