8/17/2019 Stpm p3

1/10

8/17/2019 Stpm p3

2/10

 

4 The graph below shows the displacement of the particles in a rope caused by a travellingwave at a particular time.

Which statement is not true of the motion of the particles in the rope.

A The speed of the particle at P  is maximum.

B The acceleration of the particle at Q is zero.

C The energy of the particle at R is entirely potential energy.

D The energy of the particle at S  is entirely kinetic energy,

5 A person can hear a sound of intensity 1.0 x 10-11 W m-2. The sound level increases by

35 dB when the man uses a hearing aid. What is the new intensity of the sound heard?

A 3.50 x 10-11 W m-2 B 3.50 x 10-10 W m-2

C 3.16 x 10-9 W m-2 D 3.16 x 10-8 W m-2

6 A sound source moving towards a stationary observer produces a sound of velocity vand wavelength A. What is the velocity and wavelength of the sound detected by the

Observer

Velocity Wavelength

A  ν  λ  

B  ν  < λ  

C > ν  < λ  

D > ν  > λ  

8/17/2019 Stpm p3

3/10

7 The diagram below shows a light bulb placed in front of an arrangement of a convex and

concave lens of focal lengths 20 cm and 10 cm respectively. The lenses are arranged

coaxially.The distances between the lenses is 20 cm.

For the light rays from the concave lens to emerge parallel , the distance of the light bulb

from the convex lens should be,

A 10 cm B 12 cm C 20 cm D 60 cm

8 To reduce reflection as much as possible , a glass surface is covered with a thin

transparent film. The thickness of the film must be same as

A the wavelength of light in the glass

B the wavelength of light in the film

C half of the wavelength of light in the glass

D one –  fourth of the wavelength of light in the film

9 An object is placed 5 cm from a convex mirror with a radius of curvature of 20 cm. The

image formed is

A 3.3 cm in front of the mirror and is diminished

B 3.3 cm behind the mirror and is enlarged

C 4 cm in front of the mirror and is diminished

D 4 cm behind the mirror and is enlarged

20 cm

Light bulb

8/17/2019 Stpm p3

4/10

10 In a Young’s double slit experiment, when the distance between the slits and screen is

increased

A the fringe separation decreases the maximum intensity of bridge fringes decreases

B the fringe separation decreases the maximum intensity of bridge fringes increases

C the fringe separation increases the maximum intensity of bridge fringes decreases

D the fringe separation increases the maximum intensity of bridge fringes increases

11 When light of wavelength 350 nm is incidented on a metal surface, photoelectrons withmaximum kinetic energy 2.0 eV are emitted from the surface. What is the maximum

wavelength of light that can emit photoelectrons from the metal?

A 200 nm B 580 nm C 620 nm D 802 nm

12 The diagram below shows the first order diffraction image observed from a reflected X-

ray beam.

What is the separation , d ,  between adjacent atomic planes in the crystal if the wavelength

of the X –  ray is 1.20 x 10-10 m ?

A 1.16 x 10-10

 m

B 1.24 x 10-10 m

C 1.96 x 10-10 m

D 2.32 x 10-10 m

Incident

X – ray

 beam

Reflected

X – ray

 beam

750 

d

8/17/2019 Stpm p3

5/10

13 The diagram below shows the energy levels of the hydrogen atom.

Which transition produces radiation of wavelength 436 nm?

A n = 4 to n = 1

B n= 4  to n = 2

C n = 5 to n = 1

D n = 5 to n = 2

14 If the masses of the proton, neutron, electron and atom are m p, mn , me and mc

respectively. Find the mass defect  Δ m of the nucleus .

A  Δ m  = 6 m p + 6 mn - mc 

B  Δ m  = 6 m p + 6 mn  –  6 me - mc 

C   Δ m  = 6 m p + 6 mn + 6 me - mc

D  Δ m  = 6 m p + 6 mn +6 me  –  6 mc

15 Which of the following quantities is not conserved in a nuclear reaction ?

A Mass B Momentum C Atomic number D Nucleon number

C 126

C 126

8/17/2019 Stpm p3

6/10

Section B [15 marks]

 Answer all questions in this section.

16. (a) An object is moving with simple harmonic motion. The distance between two consecutive points at which the speed of the object is zero is 10.0 cm. The time taken by the object to move

 between the two points is 1.5 s.

(i) Calculate the amplitude of the motion of the object. [ 1 mark  ]

(ii) Calculate the frequency of the motion of the object. [ 2 marks ]

(iii) Calculate the maximum acceleration of the object. [ 2 marks ]

(iv) calculate the magnitude of the velocity of the object when it is 3.0 cm from the equilibrium

 position. [ 2 marks ]

8/17/2019 Stpm p3

7/10

17  (a) The energy of the electron in a hydrogen atom is given by the equation

En = −13.6

 eV, where n = 1,2,3,…… 

(i) Calculate the energy of the electron in the ground state in joules [ 1 mark  ]

(ii) An electron in a hydrogen atom makes a transition from energy level n=4 to energy level

n =2 and emits a photon. Find the energy emitted by the atom in eV and determine the

wavelength of the emitted photon. [ 4 marks ]

(b) An electron has a de Broglie wavelength of 1.5 x 10-10

 m.

Calculate

(i) the momentum of the electron . [ 1 mark  ]

(ii) the kinetic energy of the electron . [ 1 mark ]

(iii) the potential difference required to accelerate the electron. [ 1 mark  ]

8/17/2019 Stpm p3

8/10

Section C [30 marks]

 Answer any two questions in this section.

18 (a) A progressive wave on a stretched string is represented by the equation .

y = 0.03 sin ( 4.0 t –  0.25x )with x and y in metre and t in seconds.

(i) Explain the meaning of x and y in the equation. [ 2 marks ]

(ii) What is the speed of this progressive wave ? [ 3 marks ]

(b) A person who stands by the side of a railway track finds that the apparent frequency

of the train whistle changes from 700 Hz while the train approaches the person from far

to 580 Hz when the train passes by her and moves away from her. It is known that the speed of

sound in air is 330 m s

-1

, what is(i) the speed of the train [ 2 marks ]

(ii) the real frequency of the whistle ? [ 2 marks ]

(c) A thin biconvex lens made of glass with refractive index 1.55 has surfaces with equal

radius of curvature 15.0 cm. An object is placed 20.0 cm on the principal axis to the left of the

lens.

(i) determine the focal length of the lens [ 2 marks ]

(ii) determine the image position. [ 1 mark  ]

(iii) the surface of the lens is to be coated with a translucent material of

refractive index 1.35 so that light of wavelength 500 nm will not be refracted . Calculate the

minimum thickness of the coating. [ 3 marks ]

19  (a)(i) State two observations from the experiment on photoelectric effect that cannot be

explained with the wave theory [ 2 marks ]

(ii) Monochromatic light with wavelength 300 nm illuminates the surface of a potassiummetal of work function 2.50 eV. Calculate the maximum speed of the photoelectrons emitted.

[3 marks]

(iii) Sketch the graph for the maximum speed of photoelectrons against the frequency of

the incident rays. [ 2 marks ]

8/17/2019 Stpm p3

9/10

  (b) (i) Explain the difference between the process of production of continuous X-rays with

the process of production of line X-rays from an X-ray tube. [ 4 marks ]

(ii) Why is the line X-rays the characteristic of the target metal in the X-ray tube ?

[ 1 mark  ]

(iii) The accelerating potential difference across an X-ray tube using copper as target

is 5.5 kV. Calculate the minimum wavelength of the X-rays produced. [ 2 marks ]

(iv) A wavelength of the copper line X-rays is 1.54 x 10-10 m. State whether the line X-

rays can be produced by the X-ray tube in (b) (iii) above. [ 1 mark  ]

20  (a) Nuclear fission is carried out using thermal neutrons. What is meant by nuclear fission 

and thermal neutrons ? [ 2 marks ]

(b) A reaction of nuclear fission is represented by the following equation.

92235   + 0

1   → 55141   + 37

93   + 2  01  

[ mass of 92235   = 235.04392 mass of 55

141  = 140.91963 u

mass of 3793  = 92.92157 u mass of 0

1  = 1.00867 u ]

(i) calculate the mass defect of the above reaction. Explain, in terms energy, why the mass

defect occurs [ 4 marks ]

(ii) In an atomic bomb, energy is released from the fission of U-235 according to the above

equation. One atomic bomb uses 100 kg of U-235. What is the reduction in mass which

occurs if all of U-235 undergo fission ? [ 3 marks ]

(iii) How much energy is released in the fission of U-235 in (b) (ii) above ? [ 3 marks ]

(iv) The strength of an atomic bomb is the total energy released when the bomb explodes

and this is stated in megatonnes of TNT. One megatonne of TNT releases 2.6 x 1028

MeV ofenergy. Determine the strength , in megatonnes of TNT ,of the atomic bomb in (b) (ii)

above. [ 3 marks ]

8/17/2019 Stpm p3

10/10

Values of Constants ( Nilai Pemalar)

Acceleration of free fall (Pecutan jatuh bebas)  g  = 9.81 m s-2

 

Avogadro constant (Pemalar Avogadro)  N A = 6.02 x 1023

 mol-1

 

Boltzmann constant (Pemalar Boltzmann) k  = 1.38 x 10-23

 J K -1

 

Gravitational constant (Pemalar gravity) G = 6.67 x 10-11

 Nm2kg

-2 

Magnitude of electronic (Magnitud cas electron) e = 1.60 x 10-19

 Ccharge

Mass of the Earth (Jisim Bumi) ME = 5.97 x 1024 kg

Mass of the Sun (Jisim Matahari) MS = 1.99 x 1030

 kg

Molar gas constant (Pemalar gas molar) R = 8.31 J K -1

 mol-1

 

Permeability of free space (Ketelapan ruang bebas)  0 = 4 x 10-7

 Hm-1

 

Permittivity of free space (Ketelusan ruang bebas)  0 = 8.85 x 10-12 Fm-1 

≈  

  

 

 36

1 x 10

-9 F m

-1 

Planck constant (Pemalar Planck) h = 6.63 x 10-34

 J s

Radius of the Earth (Jejari Bumi) R E = 6.38 x 106 m

Radius of the Sun (Jejari Matahari) R S = 6.96 x 108 m

Rest mass of electron (Jisim rehat electron) me = 9.11 x 10-31 kg

Rest mass of proton (Jisim rehat proton) m p = 1.67 x 10-27 kg

Speed of light in free space (Laju cahaya dalam ruang bebas) c = 3.00 x 10

8

 ms

-1

 

Stefan-Boltzmann constant (Pemalar Stefan-Boltzmann)  = 5.67 x 10-8 Wm-2K -4 

Unified atomic mass unit (Unit jisim atom bersatu) u = 1.66 x 10-27

 kg