PHYS454 & PHYS455
MCQ Exam
2nd Semester (1436-1437)
[h=6.625x10-34J.s, c=3x108 m/s, o=8.85x10-12 C2/N. M2 , me=9.11x10-31 kg, e=1.6x10-19 C , R=1.097x107 m-1 ]
Name:
ID:
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What is in the center of the Rutherford
model?
a Multiple electrons
b A single proton
c Neutrons
d A nucleus
The photon, the energy of electromagnetic
radiation, has energy
a mc2
b ℎ/𝜆
c ℏ𝑘
d ℎ𝑓 = ℏ𝑤
The ratio of the energy of a photon of
wavelength 4000 Å radiation to that of
2000 Å radiation is
a ¼
b 4
c ½
d 2
Discovery of the nucleus of an atom was due
to the experiment carried out by
a
Bohr
b Mosley
c
Rutherford
d Thomson
A particle is performing circular motion
with a tangential velocity v. If r is the radius
of the circle, then the particle acceleration is
given by
a v/r
b
v2/r
c v/r2
d
v2/r2
An electron and a proton are accelerated
through the same potential difference. The
ration of their De Broglie wave length will
be --
MCQ [AMP]
a
𝑚𝑝
√
𝑚𝑒
b 𝑚𝑝 ⁄𝑚𝑒
c 𝑚𝑒 ⁄𝑚𝑝
d 1
7 In the natural atom
a
The atomic number is equal the
electron number
b The neutron number is larger than the
proton number
c The electron number is smaller than the
neutron number
d The atomic number is larger than the
electron number
8 The energy levels of the H-atom according
to the Bohr model is
a Fixed with increasing the radius of the
orbital level
b Increasing with increase the radius of
the orbital
c Decreasing with increase the radius
orbital
d All the above answers
9 Which of the following are isoelectronic
with one another (note: Z(Na)=11,
Z(Ne=10), Z(O=8), Z(K=19)
a
Na  and Ne
b
K  and O
c
Ne and O
d
Na  and K 
10 If f1 and f2 are the frequencies of the
electron in the first and second orbits of the
hydrogen atom respectively, the (f1/f2) is :
a 8
b 2
c 4
d 1
11 If n (Principal quantum number), l (Orbital
angular momentum quantum number) & m
(Magnetic angular momentum quantum
number) are quantum numbers associated
with Hydrogen atom, the angular part of its
Page 1
PHYS454 & PHYS455
MCQ Exam
2nd Semester (1436-1437)
[h=6.625x10-34J.s, c=3x108 m/s, o=8.85x10-12 C2/N. M2 , me=9.11x10-31 kg, e=1.6x10-19 C , R=1.097x107 m-1 ]
wavefunction depends upon the quantum
numbers
a l and m
12
13
14
15
16
17
b Only m
c Only l
d n and l
4 electron volt is
a 2x10-19 J
b 6.4x10-19 J
c 3.2x10-19 J
d 4.6x10-19 J
The Heisenberg’s uncertainty principle is
expressed as:
a ∆x · ∆px = h /4π
b ∆x · ∆px ≤ h /4π
c ∆x · ∆px ≥ h /4π
d All the above
Electron moving with velocity (v) in a
circular Bohr orbit of radius r produces a
current
a i= e/T
b
i=eω/2π
c a and b
d None of above
The fourth sub-state of an atom can have a
maximum of
a 2 electrons
b 10 electrons
c 14 electrons
d 6 electrons
Internal magnetic field produces torque
which results in precession of and about
their sum, the total angular momentum:
a J = L+S
b J=L-S
c J=S - L
d J = L/S
For a current I flowing in a circle enclosing
an area A, µ (magnetic moment) is defined
to be
a µ =i.A
b A= i. µ
MCQ [AMP]
18
19
20
21
c µ= ixA
d i= µ.A
The electron configuration for gallium
(31Ga)is:
a [Ar]4s24d104p1
b [Ar]4s23d103p1
c
[Ar]5s23d104p1
d [Ar]4s23d104p1
According Bohr model for the hydrogen
atom, which of the following orbitals has the
lowest energy
a 4s
b 4d
c 4p
d They all have the same energy
The orbital degeneracy of hydrogen atom
energy levels equals
a n-1
b n
c n+1
d 2n+1
The energy released when an atom
takes an electron is called
a
internal energy
b dissociation energy
c
binding energy
d electron affinity
22 Which of the following refer to the
basic categories associated with the
energy of a single molecule in a
gaseous phase?
a
nuclear, electronic, interval
b
electronic, translation, rotation,
vibration
c
ionic, covalent, hydrogen, Van
der Waals
d
translation, rotation, vibration
23 Assume a diatomic molecule can be
considered to be two point masses
separated by a distance r. The center
of mass of the system is located a
distance x from m1, equal to
a
m1r/(m1 + m2)
Page 2
PHYS454 & PHYS455
MCQ Exam
2nd Semester (1436-1437)
[h=6.625x10-34J.s, c=3x108 m/s, o=8.85x10-12 C2/N. M2 , me=9.11x10-31 kg, e=1.6x10-19 C , R=1.097x107 m-1 ]
b m2r/(m1 + m2)
c
(m1 + m2) r/m1
d (m1 + m2) r/m2
24 A diatomic molecule consists of two
point masses, m1 and m2, separated
by a distance r. If x is the distance
from m1 to the center of mass, find
the moment of inertia in terms of x
about an axis parallel to the molecular
axis through the center of mass.
a
0
b m1x2 + m2(r – x)2
c
m1m2 r2(m1m2)
d m1(r – x)2 + m2x2
25 The rotational kinetic energy of a
diatomic molecule can take the form
a
2
(1/2)
b (1/2) 2
c
[m1m2/(m1 + m2)]r2 2
d (1/2)mv2
26 An experiment determines that there
are 49 allowed rotational energies for
a diatomic molecule whose moment
2. The
of inertia is 2 x 10–46
maximum rotational kinetic energy (in
eV) is
a
0.6
b 0.2
c
0.4
d 0.8
27 The frequency of a microwave
absorbed by a molecule from the J = 3
to J = 4 rotation energy state is 4.61 x
1011 Hz. The moment of inertia of
the molecule (in kg  m2) is
a
5.7 x 10–45
b 1.4 x 10–46
c
1.1 x 10–44
d 2.9 x 10–46
MCQ [AMP]
28 The rotation spectrum of the HCl
molecule has been observed in the far
infrared, around 50 x 10–6 m. The
spacing between successive lines in
the spectrum corresponds to radiation
of wavelength equal to 5 microns (1
µm = 10–6 m). Determine the
frequency of the photon associated
with this transition.
a
6 x 1014 Hz
b
6 x 1012 Hz
c
6 x 1011 Hz
d
6 x 1013 Hz
29 . The fundamental frequency of CO is
6.42 x 1013 Hz. If the atomic masses
are 12 u and 16 u (1 u = 1.66 x 10–27
kg), find the force constant (in N/m)
for the diatomic molecule.
a
970
b
1530
c
1860
d
480
30 The energy of a molecule can
normally be divided into the following
categories:
a
rotational and vibrational
b
translational, rotational and
vibrational
c
electronic, translational,
rotational, and vibrational
d
rotational
31 In the hydrogen molecule, H2, the
separation between the protons is 10–
10 m. If the molecule is in its first
rotational energy state, what is the
angular velocity of the molecule about
its center of mass?
a
1.79 x 1013 rad/s
b
c
3.79 x 1013 rad/s
0.456 x 1013 rad/s
Page 3
PHYS454 & PHYS455
MCQ Exam
2nd Semester (1436-1437)
[h=6.625x10-34J.s, c=3x108 m/s, o=8.85x10-12 C2/N. M2 , me=9.11x10-31 kg, e=1.6x10-19 C , R=1.097x107 m-1 ]
d none of the above
32 The Laser light is:
a
Monochromatic
b divergence
c
Chromatic
d None of these
33 Laser beam production is based on the
principle of
a
Induced Absorption
b Spontaneous emission
c
Ionization
d Stimulated emission
34 Population inversion is state of the system
wherein the upper energy state, compared to
lower energy state is populated
a
Less
b More
c
Equal
d None of these
35 In the absorption process the photon is
a
Lost
b Created
c
Lost and created
d None of the above
36 In stimulated emission process the number
of coherent photons are
a
2
b 1
c
3
d None of the above
37 Which of the following is not a
characteristic of laser beam?
a
It has high penetration power.
b It is an intense monochromatic beam.
c
It is a coherent unidirectional radiation.
d It is not divergent.
38 What is stimulated emission in laser?
a
an electron from a higher energy level
falling to a lower level.
b a charged particle causing light to be
emitted from an excited atom.
c
a charged particle being emitted from
an atom as a result of a high energy
MCQ [AMP]
photon hitting the atom.
a photon causing another photon of the
same frequency to be emitted from an
excited atom
39 Absorption process is
a
Promotes molecule to a higher energy
state
b
Decreases the number of photons
c
None of the above
d
40 The Kβ x-ray line is generated by a
transition between which states?
a
2P → 1S,
b
1S → 2P
c
3P → 2S,
d
3P → 1S.
41 The Kα x-ray line is generated by a
transition between which states?
a
2P → 1S,
d
b 1S → 2P
c
3P → 2S,
d 3P → 1S.
42 The magnetic quantum number has the
values
a
0, 1, 2, ..., (n-1)
b
+1/2, -1/2
c
-n, n+1, ..., n-1,n
d
-l, ..., 0, ..., +l.
43 If atoms could contain electrons with
principal quantum numbers up to and
including n=5, how many elements could
there be?
a
182
b
110
c
60
d
28
44 The maximum value for the orbital angular
momentum of an electron with a principal
quantum number of 3 is
a
1.45x10-17 J s,
b
1.27x10-33 J s
c
2.58x10-34 J s,
d
3.66x10-34 J s
Page 4
PHYS454 & PHYS455
MCQ Exam
2nd Semester (1436-1437)
[h=6.625x10-34J.s, c=3x108 m/s, o=8.85x10-12 C2/N. M2 , me=9.11x10-31 kg, e=1.6x10-19 C , R=1.097x107 m-1 ]
45 Which of the following statements about Xray is correct?
a
X-ray is more energetic than gamma
ray.
b X-ray can be produced artificially.
c
The speed of X-ray is smaller than that
of gamma ray in air.
d X-ray will not have interference occurs
46 The splitting of atomic energy and the
associated spectrum lines when the atoms
are placed in a magnetic field is called
a
The Zeeman effect
b The stark effect
c
The photoelectric effect
d None of the above
47 Line splitting resulting from magnetic
interactions are called
a
fine structure
b Hyperfine structure
c
All the above
d
48 the energy of the characteristic x-ray emitted
from a tungsten target (z=74) when an
electron drops from an M shell (n=3 state) to
a vacancy in the K shell (n=1 state) is
a
68 keV
b 86 keV
c
60 keV
d 80 keV
49 For multi-electron atom, must consider
Coulomb interactions between its Z
electrons and its nucleus of charge +Ze.
a
Largest effects due to large nuclear
charge
b Smallest effects due to large nuclear
charge
c
Largest effects due to small nuclear
charge
d Smallest effects due to small nuclear
charge
50 Only two electrons with opposite spin can
occupy an atomic orbital. i.e., no two
electrons have the same 4 quantum numbers
MCQ [AMP]
a
b
c
d
Hund’s rule
Pauli exclusion principle
Heisenberg's uncertainty principle
All the above
Page 5