8/14/2019 [edu.joshuatly.com] Pahang STPM Trial 2011 Physics (w ans).pdf http://slidepdf.com/reader/full/edujoshuatlycom-pahang-stpm-trial-2011-physics-w-anspdf 1/45 2 1A certain physical quantity, R, is calculated using the formula: R = 4a 2 (b – c) where a, b, and c are distances. What is the SI unit for R? A cm B m C m 2 D m 3 2Which of the following is a scalar quantity? ATorque BGravitational potential CAngular momentum DAcceleration 3A car travels due east at 22 m s -1 . It makes a turn due south and continues to travel at 22 m s -1 . What is the change in velocity of the car? A22 m s -1 , due east B22 m s -1 , due south C31 m s -1 , due south- west D31 m s -1 , due south-east 4An object of mass 6 kg is acted upon by a force F which varies with time t as shown in the diagram below. If the change of momentum of the object after time T is 30 N s, what is the value of T? A3 s B 5 s C 6 s D 12 s 10 F/ N t/s O T http://edu.joshuatly.com
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8/14/2019 [edu.joshuatly.com] Pahang STPM Trial 2011 Physics (w ans).pdf
1 A certain physical quantity, R, is calculated using the formula: R = 4a2(b – c)
where a, b, and c are distances. What is the SI unit for R?
A cm B m C m2 D m
3
2 Which of the following is a scalar quantity?
A TorqueB Gravitational potential
C Angular momentum
D Acceleration
3 A car travels due east at 22 m s-1. It makes a turn due south and continues to travel
at 22 m s-1
. What is the change in velocity of the car?
A 22 m s-1
, due east
B 22 m s-1, due south
C 31 m s-1
, due south- west
D 31 m s-1, due south-east
4 An object of mass 6 kg is acted upon by a force F which varies with time t asshown in the diagram below. If the change of momentum of the object after time T is30 N s, what is the value of T?
A 3 s B 5 s C 6 s D 12 s
10
F/ N
t/sOT
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5 How much energy is dissipated in braking a 1000 kg car to a stop from an initialspeed of 20 m s-1?
A 20 000 JB 200 000 JC 400 000 J
D 800 000 J
6 A disc rotates horizontally with uniform angular velocity about an axis through itscentre. Which of the following graphs shows the correct relationship between the speed v
of a point on the disc and the distance r of the point from the centre of the disc?
7 If the angular velocity of a body performing circular motion is ω, the number of
revolutions per second is
A zero B 2πω C 2
D
2
8 The gravitational pull on a satellite on the surface of the Earth of radius R is F.
What is the gravitational pull on the satellite when it is at a height of 2R above theEarth?
A 1
2 F B
1
3 F C
1
9 F D 2F
O r
v
O r
v
O r
v
Or
v
A B
CD
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9 When an ice skater spinning about a vertical axis spread his arms outwards awayfrom the axis of rotation, his speed of rotation decreases. Which is the most likely
reason?
A His moment of inertia decreases.B His centre of gravity is lowered.
C His moment of inertia increases.D The air resistance decreases.
10 Which one of the following statements is true concerning an object executingsimple harmonic motion?
A Its velocity is never zero.
B Its acceleration is never zero.C Its velocity and acceleration are simultaneously zero.
D Its velocity is zero when its acceleration is a maximum.
11 A particle performs simple harmonic motion. Which of the following graphs
represents the variation of potential energy with displacement?
O x+xo-xo
U
O x+xo-xo
U
AB
O x+xo
-xo
U
D-xo
+xoO
C
x
U
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8/14/2019 [edu.joshuatly.com] Pahang STPM Trial 2011 Physics (w ans).pdf
B the system is critically damped.C the energy in the system is a minimum.D the driving frequency is the same as the natural frequency of the system.
13 A wave of wavelength 1.0 cm is generated by a point source on a water surface.The phase difference between a point P and the source is 10.0 radians. The distance of the
point P from the source is
A 0.016 m
B 0.032 m
C 0.048 mD 0.064 m
14
The graph shows, at a particular instant, the variation of the displacement
of the particles in a transverse progressive water wave, of wavelength 4 cm, travellingfrom left to right. Which one of the following statements is not true?
A Particles at P and R are in a phase.
B The velocity of the particle at Q is a maximum.C The particle at S is moving downwards.
D The distance PS = 3 cm.
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21 A fixed mass of an ideal gas absorbs 750 J of heat and it expands at constant pressure of 1.0 x 105 Pa from a volume of 5.0 x 10-3 m3 to a volume of 7.5 x 10-3 m3. The
internal energy of the gas
A remains unchangedB increases by 250 J
C increases by 500 JD decreases by 250J
22 The molar heat capacity of an ideal gas at constant volume is less than at constant pressure because
A work is done against external pressure when the gas expands.
B the potential energy of the molecules increases when they are further apart.C work is done against intermolecular forces as the gas expands.
D the molecules acquire greater kinetic energy at constant pressure.
23 What is the work done on two mole of an ideal gas which is compressed
isothermally at 400 K from a volume of 10 cm3 to 30 cm3?
A 2.50 kJ B 3.65 kJ C 7.30 kJ D 8.50 kJ
24 Metal is a good thermal conductor because
A the average potential energy of the molecules is high.
B it has a lot of free electronsC its molecules are very close to one another.
D the size of the molecule is large.
25 A closed container contains water at 100oC. The container of total surface area of
0.5 m2 and uniform thickness of 4.0 cm has a thermal conductivity of 0.40 W m
-1 K
-1. If a
heater of power 300 W is needed to maintain the temperature of the water, the external
temperature is
A 80oC B 60
oC C 40
oC D 20
oC
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5. A dry cell of e.m.f. V and negligible internal resistance is connected to three resistances of
resistance R1, R2 and R3 as shown in the diagram below.
Currents I , I 1, I 2 and I 3 flows through the dry cell and resistors R1, R2 and R3 respectively.When the same dry cell is connected to a resistor R , the same current I flows through the dry cell
as shown in diagram (b).
a) State the relationship between I , I 1, I 2 and I 3.
[1 mark ]
b) Hence, show that
321
1111
R R R R
[1 mark ]
c) You are given four identical resistors of resistance 3 each. Draw a diagram to show
how you would connect these four resistors to obtain an effective resistance of 4 .
[1 mark ]
I V
I1
I2
I3
R 1
R 2
R 3
Diagram (a)
I V
I3 R
Diagram (b)
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12 (a) In a Young’s double -slit experiment ,the separation of the slit is 0.5 mm and
the distance between the slits and the screen is 200 cm. When red light is used,
the distance between the centre of the interference pattern and the first bright
fringe is 0.15 cm.
(i) Find the wavelength of the red light used. [ 3 marks ]
(ii) Find the distance between the center of the interference pattern and the third
dark fringe. [ 2 marks ]
(iii) If the space between the slits and the screen is filled with a liquid of refractive
index 1.20, explain what will happen to the interference pattern on the screen.[ 2 marks ]
(b) A beam of parallel monochromatic light falls on a single slit 0.1 mm wide.
A convex lens of focal length of 50 cm is placed in front of the slit to focus the
light that passes through the slit onto a white screen . If the width of the centralmaximum of the diffraction pattern produced on the screen is 3.5 mm,
determine the wavelength of the monochromatic light used. [ 4 marks ]
(c) Light from a hydrogen flame is incident normally onto a diffracting gratingwhich has 3000 lines per cm. If the wavelength of the line α and δ for the
hydrogen atom are 655 nm and 410 nm respectively, determine the angular
separation between the two lines in the second order of the spectrum produced
by the diffracting grating [ 4 marks ]
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In diagram (a)The magnet will drop under the influence of gravity ignoring air resistance.
In diagram (b)When the magnet falls, the conductor experience a change in magnetic field.According to Faraday’s Law, a current will be induced in the conductor
………………………………..(1)
According to Lenz’s Law the direction of current induced in the conductor will produce amagnetic field that causes a force that acts upwards on the magnet.
………………………………….(1)
The nett force acting downwards will be smaller than in figure (a) ……….(1)
According to Newton’s second law of motionIts acceleration downwards will also be smaller. …………………..(1)
Thus the time taken will be longer.
7.(a)
Inverting amplifier…………………………(1)
(b)Integrator………………………………….(1)
(c)
dt V CR
V io 1 …………………………(1)
=
dt t 2sin5105102
166
= dt t 2sin5.0
=
2
2cos5.0
t ……………..(1)
2
2cos t
= 0.25cos2t or
4
2cos t ……………….(1)
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8/14/2019 [edu.joshuatly.com] Pahang STPM Trial 2011 Physics (w ans).pdf
8(a)(i)If X-rays are diffracted, it shows that X-rays are waves since diffraction is a wave property. ……………………………..(1)
(ii)
The atoms in the crystalline solid are arranged in parallel planes with the atomic planeseparation of the same order of magnitude as the wavelength of X-rays…………………………….(1)
(b)2d sin = n
0
10
60sin2
105.13
d ………………(1)
=2.60 x 10-10 m ………………(1)
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8/14/2019 [edu.joshuatly.com] Pahang STPM Trial 2011 Physics (w ans).pdf
Strong nuclear force is short range compared to electrostatic repulsive forcewhich has larger range.
Strong nuclear force is much stronger than electrostatic repulsive forceStrong nuclear force does not depend on charges but electrostatic forcedepends on charges
m p = mn = m ( assumption )
mass of nucleus = Am
volume = 4/3 π r 3 = 4/3 π ( R o A1/3 ) = 4/3 π A R o3
density = Am / 4/3 π A R o3 = 3m / 4π R o
3
= constant
1mark
1 mark
1 mark
1 mark
1 mark
1 mark
(b) (i)
(ii)
(iii)
(c)
∆ m = ( 235.0439 + 1.0087) – ( 147.9314 + 84.9156 + 3 X 1.0087 )
= 0.1795 u∆ E = ∆ m c2 = (0.1795 x 1.66 x 10-27 ) X ( 3x 108 )2
= 2.682 x 10-11 J
5 x 106 x 10 x 60x60 = 1.8 x 1011 J
With 30 % efficiency , actual energy produced is 1.8 x 1011 / 0.3
= 6.0 x 1011 J
No. of atoms used = 6 x 1011 / 2.682 x 10-11 = 2.237 x 1022
No. of atoms used in 10 years = 10 x 180 x24 x 2.237 x1022/ 10
= 9.664 x 1025
No. of moles = 9.664 x 1025 / 6.02 x1023 = 160.53
Mass of 235 U used = 160.53 x 235.0439 = 37.73 kg
E = mc2 = 2 x me c2 = 2 x 9.11 x 10-31 x 9 x 1016 J
Energy of each γ photon = 9.11 x 10-31 x 9 x 1016 J= 8.20 x 10-14 J