Download Physics (Sample Paper 1)

UNIVERSITY ENTRANCE EXAMINATION
PHYSICS
Duration
: 2 hours
Please read the following instructions carefully.
1.
This paper is made up of 50 Multiple-Choice questions and comprises
TWENTY (20) printed pages.
2.
Do not write on the question paper.
3.
Answer all questions and indicate your answers on the answer sheet
provided. Marks will not be deducted for wrong answers.
4.
Do not take any paper, including the question paper or unused answer
sheets, out of the examination hall.
1
USEFUL INFORMATION:
Acceleration due to gravity, 𝑔 ≈ 9.80 m s −2
Avogadro’s number, 𝑁𝐴 ≈ 6.022 × 1023 particles⁄mol
Universal gas constant, 𝑅 ≈ 8.314 J K −1 mol−1
Gravitational constant, 𝐺 ≈ 6.673 × 10−11 N m2 kg −2
Coulomb constant, 𝑘 ≈ 8.99 × 109 N m2 C−2
Magnitude of charge of electron, 𝑒 ≈ 1.602 × 10−19 C
Mass of electron, 𝑚𝑒 ≈ 9.109 × 10−31 kg
Mass of proton, 𝑚𝑝 ≈ 1.673 × 10−27 kg
Mass of neutron, 𝑚𝑛 ≈ 1.675 × 10−27 kg
Speed of light, 𝑐 ≈ 2.998 × 108 m s −1
Planck’s constant, ℎ ≈ 6.626 × 10−34 J s
Atomic mass unit, 𝑢 ≈ 1.661 × 10−27 kg
2
1.
What is the SI unit for acceleration?
A
B
C
D
E
2.
kg
J
N
m/s
m/s2
A uniform beam in a symmetrical roof structure has a weight of 180 N. It is
supported evenly in two places X and Y at a distance 3.0 m apart. A load is
placed on the beam a distance of 0.80 m from X. The support provided by
Y is 220 N.
What is the value of the load?
A
B
C
D
E
3.
N
N
N
N
N
An unbalanced force of 40 N keeps a 5-kg object traveling in a circle of radius
2 m on a horizontal plane. What is the speed of the object?
A
B
C
D
E
4.
270
490
520
830
980
8 m/s
2 m/s
16 m/s
4 m/s
6 m/s
A student is standing in an elevator that is accelerating upward. The force
that the student exerts on the floor of the elevator must be
A
B
C
D
E
less than the weight of the student when at rest.
greater than the weight of the student when at rest.
less than the force of the floor on the student.
greater than the force of the floor on the student.
The answer is not certain because of insufficient information.
3
5.
An object falls freely with constant acceleration a from above three light
gates. It is found that it takes a time t to fall between the first two light
gates a distance of s1 apart. It then takes an additional time, also t, to fall
between the second and third light gates a distance s2 apart.
What is the acceleration in terms of s1, s2 and t?
A
B
C
D
E
6.
s2  s1 
t2
s2  s1 
2t 2
2s 2  s1 
3t 2
2s 2  s1 
t2
4s 2  s1 
t2
Two cars, initially next to each other and at rest, accelerate in the same
straight line at different uniform rates. After 3 s, they are 12 m apart.
If they continue to accelerate at the same rate, how far apart will they be
6 s after they started?
A
B
C
D
E
18
24
36
48
60
m
m
m
m
m
4
7.
A meteorite falls freely towards the center of an isolated spherical planet of
radius R. When it reaches the surface of the planet, its acceleration is gs.
What is its acceleration when at a height 2R above the surface?
A
B
C
D
E
8.
A car accelerates uniformly from rest along a level road. The effects of air
resistance on the car are negligible. The car travels 12 m in the time
between 1 s and 2 s after starting. How far does it travel in the time between
3 s and 4 s after starting?
A
B
C
D
E
9.
1
gs
9
1
gs
4
1
gs
3
1
gs
2
3
gs
4
28
35
48
64
76
m
m
m
m
m
A stone is dropped from a bridge. What happens to the magnitude of the
acceleration and the speed of the stone as it falls? [Neglect any friction.]
A
B
C
D
E
Both acceleration and speed increase.
Both acceleration and speed remain the same.
Acceleration increases and speed decreases.
Acceleration remains the same and speed increases.
The answer is uncertain due to insufficient information.
5
10.
A stone is thrown upwards from a point at the edge of a cliff. After the stone
has reached its maximum height, it falls past the cliff edge to the beach, as
shown.
The initial vertical component of the velocity of the stone is 10 ms-1. The
time taken between the stone passing the edge of the cliff on its way down
and hitting the beach is 1.2 s.
Ignoring air resistance, what is the height of the cliff?
A
B
C
D
E
11.
5m
7m
12 m
19 m
26 m
A wire is stretched elastically by a force of 200 N, causing an extension of
4.00 mm. The force is then steadily increased to 250 N. The wire still
behaves elastically.
How much extra work is done in producing the additional extension?
A
B
C
D
E
0.225 J
0.250 J
225 J
250 J
270 J
6
12.
A constant force F is applied to a stationary object of mass m on a
frictionless surface. A constant acceleration increases the velocity of the
object to some value v in a time t. It covers a distance s during this time.
Which value of kinetic energy is given to the object?
A
Fst
B
Fv
C
Fs
D
ms
2t
ms
4t
E
13.
A stone of mass m moves radially away from Earth. For a small distance x
above the Earth’s surface, the variation with x of the stone’s gravitational
potential energy Ep is shown as follows:
At point P, a distance d from Earth, the potential energy of the stone is E
and the rate of change of potential energy with distance is R.
What is the force acting on the stone?
A
B
C
D
E
E
d
mE
d
mR
0.5R
R
7
14.
15.
An object of mass m is travelling with velocity v. Which equation gives the
momentum p of the object in terms of either m or v and its kinetic energy
Ek ?
2Ek
m
A
p
B
p  2Ek v
C
p
D
p  Ek m
E
p  2Ek m
2Ek
d
v
The diagram shows two spheres of masses 2 kg and 3 kg moving at
constant speed along a straight line towards one another.
The speeds of the spheres are 4 ms-1 and 6 ms-1 respectively. The spheres
collide elastically. Which statement explains why the spheres cannot come
to rest at the same time?
A
B
C
D
E
16.
The impulses during the collision are not equal and opposite.
The masses of the two spheres are not equal.
The momenta of the spheres are not equal and opposite.
They do not stick together after the collision.
The speeds of the spheres are not equal.
What is the mean speed and the mean angular velocity of the Earth in its
orbit around the Sun? (The mean radius of the orbit is 1.50 x 1011 m.)
A
B
C
D
E
Speed / m s-1
2.99 x 104
2.99 x 104
1.09 x 107
1.09 x 107
2.99 x 107
Angular Velocity / rad s-1
1.99 x 10-7
1.72 x 10-2
1.72 x 10-2
7.27 x 10-5
7.27 x 10-5
8
17.
A stone of mass m is attached to a string. The stone is rotating in a vertical
circle of radius r with a constant angular speed  as shown.
The acceleration of free fall is g. What is the variation in magnitude of the
tension in the string during one revolution of the stone?
A
B
C
D
E
18.
zero
2mg
mr 2
2mr 2
4mr 2
The motor M in a crane is used to lift a total mass of 1400 kg through a
height of 2.0 m at a constant speed of 1.6 ms-1. The motor is 20% efficient.
What is the minimum input power to motor M?
A
B
C
D
E
11 kW
22 kW
110 kW
140 kW
180 kW
9
19.
The diagram shows a ball which has been thrown and is being acted on by
air resistance. Which labelled arrow shows the direction of the resultant
force when the ball is located at the highest point of its flight as shown in
the following figure?
20.
An immersion heater takes time T1 to raise the temperature of a mass M
of a liquid from a temperature t1 to its normal boiling point t2. In a further
time T2, a mass m of the liquid is vaporized. If the specific heat capacity of
the liquid is c and heat losses to the atmosphere and to the containing vessel
are ignored, the specific latent heat of vaporization is
A
Mct 2  t1 T2
mT1
B
mct 2  t1 T2
MT1
C
Mct1T2
mT1
D
mT1
Mct 2  t1 T2
E
mT1
Mct1T2
10
21.
Four waves are described by the following expressions, where distances are
measured in meters and times in seconds.
I
y = 0.12 cos(3x - 21t)
II
y = 0.15 sin(6x + 42t)
III
y = 0.13 cos(6x + 21t)
IV
y = -0.23 sin(3x - 42t)
Which of these waves have the same period?
A
B
C
D
E
22.
Consider a closed pipe of length L. What are the wavelengths of the three
lowest tones produced by this pipe?
A
B
C
D
E
23.
I and III, and also II and IV
I and IV, and also II and III
I and II, and also III and IV
All of them have the same period.
They all have different periods.
16L, 4L, L
4L, 2L, L
2L, L, L/2
2L, L, 2L/3
4L, 4L/3, 4L/5
Two in-phase loudspeakers that emit sound with the same frequency are
placed along a wall and are separated by a distance of 5.00 m. A person is
standing 12.0 m away from the wall, equidistant from the loudspeakers.
When the person moves 1.00 m parallel to the wall, she experiences
destructive interference for the first time. What is the frequency of the
sound? The speed of sound in air is 343 m/s.
A
B
C
D
E
211
256
422
512
674
Hz
Hz
Hz
Hz
Hz
11
24.
25.
Two charges, Q1 and Q2, are separated by a certain distance R. If the
magnitudes of the charges are doubled and their separation is also doubled,
then what happens to the electrical force between these two charges?
A
B
It is doubled.
It changes by a factor of 3.
C
D
E
It is reduced by a factor of
It is quadrupled.
It remains the same.
Two point charges of magnitudes +7.00 μC, and -9.00 μC are placed along
the x-axis at x = 0 cm and x = 40.0 cm, respectively. Where must a third
charge be placed along the x-axis so that it does not experience any net
force because of the other two charges?
A
B
C
D
E
26.
2.
0.200 m
2.99 m
-0.187 m
-2.99 m
0.187 m
A positive point charge +q is located at each of the three vertices A, B, and
C of an equilateral triangle ABC as shown. Each side of the triangle is of
length a. A point charge Q (that may be positive or negative) is placed at
the mid-point between B and C.
q
A
a
B
a
Q
q
q
a/2
a/2
C
Determine an expression for the magnitude and sign of Q so that the net
force on the charge at A is zero newtons.
A
3 3

Q   q
 4 


B
3 3

Q   q
 4 


C
D
E
4 3

Q   q
 3 


 3 

Q   q
4 3
4 3

Q   q
 3 


12
27.
An electron, initially at rest is accelerated through a potential difference of
550 V. What is the speed of the electron due to this potential difference?
A
B
C
D
E
28.
106
106
106
106
106
m/s
m/s
m/s
m/s
m/s
double.
quadruple.
be cut in half.
be cut in fourth.
not change.
The length of a certain wire is doubled and at the same time its radius is
tripled. What is the change in the resistance of this wire?
A
B
C
D
E
30.
×
×
×
×
×
A capacitor consists of a set of two parallel plates of area A separated by a
distance d. This capacitor is connected to a battery and charged until its
plates carry charges +Q and -Q. If the separation between the plates is
doubled, the potential difference between the plates will
A
B
C
D
E
29.
1.44
1.59
6.10
18.7
13.9
It
It
It
It
It
stays the same.
is reduced by a factor of 4.5.
is doubled.
is tripled.
is quadrupled.
A number of resistors are connected across points A and B as shown.
What is the equivalent resistance between points A and B?
A
B
C
D
E
4Ω
6Ω
8Ω
10 Ω
12 Ω
13
31.
Five resistors are connected as shown. The potential difference between
points A and B is 25 V.
3.6 
3.5 
A
1.8
2.4
5.1
B
How much energy is dissipated in the 1.8-Ω resistor in 4.0 seconds?
A
B
C
D
E
32.
18
28
55
64
93
J
J
J
J
J
A wire in the shape of an "M" lies in the plane of the paper. It carries a
current of 2.0 A, flowing from A to E. It is placed in a uniform magnetic field
of 0.85 T in the same plane, directed as shown.
What is the magnitude and direction of the force acting on section DE of
this wire?
A
B
C
D
E
0.30
0.12
0.30
0.12
0.20
N
N
N
N
N
perpendicular
perpendicular
perpendicular
perpendicular
perpendicular
out of the page
into the page
into the page
out of the page
out of the page
14
33.
Two long parallel wires carry currents of 20 A and 5.0 A in opposite
directions. The wires are separated by 0.20 m. At what point between the
two wires are the contributions from the two wires the same?
A
B
C
D
E
34.
A proton, moving west, enters a magnetic field of a certain strength.
Because of this magnetic field the proton curves upward. What is the
direction of this magnetic field?
A
B
C
D
E
35.
0.040 m from the 20 A wire
0.080 m from the 20 A wire
0.12 m from the 20 A wire
0.16 m from the 20 A wire
0.18 m from the 20 A wire
towards the
towards the
towards the
towards the
downward
west
east
south
north
A conducting rod with a length of 27.0 cm is placed on a U-shaped metal
wire that includes a light bulb with a resistance of 60.0 Ω as shown. A
constant magnetic field with a strength of 0.600 T is applied perpendicular
into the paper.
An applied force moves the rod to the right with a constant speed of 6.00
m/s. What is the power consumed by the light bulb?
A
B
C
D
E
4.00
15.7
11.6
7.57
25.4
mW
mW
mW
mW
mW
15
36.
The magnetic field and the number of turns of a coil of wire are doubled,
while its area is reduced by a factor of 2. Assuming that all the other
parameters remain the same, what happens to the induced emf in that coil
of wire?
A
B
C
D
E
37.
is doubled.
is reduced by a factor of 2.
is quadrupled.
is reduced by a factor of 4.
stays the same.
The graph below shows the voltage across and the current through a single
circuit element connected to an ac generator. What is the reactance of this
element?
A
B
C
D
E
38.
It
It
It
It
It
20
25
30
35
40





The figure below shows a simple ac circuit consisting of an inductor
connected across the terminals of an ac generator.
If the frequency of the ac generator is decreased by a factor of four, what
will happen to the inductive reactance on the inductor?
A
B
C
D
E
It
It
It
It
It
decreases by a factor of 4.
decreases by a factor of 8.
increases by a factor of 2.
increases by a factor of 4.
increases by a factor of 8.
16
39.
A certain part of the electromagnetic spectrum ranges from 200 nm to 400
nm. What is the lowest frequency associated with this portion of the
spectrum?
A
B
C
D
E
40.
1.50
7.50
7.50
7.50
1.50
×
×
×
×
×
1014
1013
1014
1015
1015
Hz
Hz
Hz
Hz
Hz
The figure shows the path of a ray of light as it travels through air and
crosses a boundary into water. The index of refraction of water for this light
is 1.33.
60°
air
30°
water
What is the angle of refraction for this situation?
A
B
C
D
E
41.
0.37°
0.65°
22°
41°
60°
A ray of light is normally incident on face ab of a plastic prism with an index
of refraction n = 1.20 as shown below.
a
incident ray

b
c
Determine the largest value of the angle so that the ray is totally reflected
at the face ac if the prism is immersed in air.
A
B
C
D
E
21°
34°
69°
78°
Total internal reflection will not occur for any value of .
17
42.
The figure is a scaled diagram of an object and a converging lens
surrounded by air. Only one focal point, F, of the lens is shown.
The index of refraction of this lens is 1.51 for red light and 1.53 for blue
light. Blue light is focused at the point F. Which one of the following
statements is true concerning the focal point for red light?
A
B
C
D
E
43.
is
is
is
is
is
also at F.
very close to D.
very close to the lens.
to the left of and close to F.
to the right of and close to F.
If the wavelength of light in Young's two-slit experiment is decreased, which
one of the following statements is true of the interference pattern?
A
B
C
D
E
44.
It
It
It
It
It
The distance between the minima stays the same.
The distance between the maxima decreases.
The distance between the maxima stays the same.
The distance between the maxima increases.
Impossible to tell without knowing the wavelength of light in use.
In a single slit diffraction experiment, the width of the slit is 3.1 × 10 -5 m
and the distance from the slit to the screen is 2.2 m. If the beam of light of
wavelength 600 nm passes through the slit and forms a diffraction pattern
on the screen, what is the linear distance on the screen from the center of
the diffraction pattern to the first dark fringe?
A
B
C
D
E
2.1
4.3
6.3
7.4
8.5
cm
cm
cm
cm
cm
18
45.
A monochromatic beam of light of wavelength 600 nm is incident normally
on a diffraction grating with a slit spacing of 1.70 × 10-4 cm. What is the
angle for the first order maximum?
A
B
C
D
E
46.
A 60-W bulb is operating at an efficiency of 6.20%. What is the number of
photons per second given off by the bulb assuming the wavelength of light
to be 580 nm?
A
B
C
D
E
47.
5.42
10.8
16.2
21.7
25.3
×
×
×
×
×
1018
1018
1018
1018
1018
photons/s
photons/s
photons/s
photons/s
photons/s
When you decrease, by a factor of two, the wavelength of the light causing
photoelectrons to be emitted from a metal surface, the kinetic energy of
the photoelectrons will
A
B
C
D
E
48.
10.5°
12.1°
16.4°
18.2°
20.7°
decrease by a factor of 2.
double
more than double.
increase by a factor of √2.
decrease by a factor of √2.
An electron is moving with the speed of 1780 m/s. What is its de Broglie
wavelength?
A
B
C
D
E
409
302
205
420
502
nm
nm
nm
nm
nm
19
49.
What is the wavelength of the emitted photon if an electron in the hydrogen
atom makes a transition from n = 2 state to the ground state?
A
B
C
D
E
50.
121.5
203.1
243.0
388.8
411.1
nm
nm
nm
nm
nm
Fermium-253 has a half-life of 3.00 days. A sample of fermium has
7.37 × 107 nuclei. How long will it take for there to be only 3.36 × 106
fermium nuclei in this sample?
A
B
C
D
E
2.75
9.80
13.4
15.7
58.6
days
days
days
days
days
END OF PAPER
20