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Name: No. IC:.

PENGGAL 2 960/2 STPM 2015

JABATAN PENDIDIKAN NEGERI KELANTAN

SIJIL TINGGI PERSEKOLAHAN MALAYSIA

PHYSICS 2 (FIZIK 2)

MODUL 2 One and a half hours ( Satu jam setengah)

Instructions to candidates:

DO NOT OPEN THIS QUESTIONS PAPER UNTIL YOU

ARE TOLD TO DO SO.

There are fifteen questions in Section A. For each questions, four

choices of answers are given. Choose one correct answer and

indicate it on the Multiple-choice Answer Sheet provided. Read the

instructions on the Multiple-choice Answer Sheet very carefully.

Answer all questions. Marks will not be deducted for wrong answers.

Answer all questions in Section B. Write your answers in the

spaces provided.

Answer any two questions in Section C. All essential working

should be shown. For numerical answers, unit should be quoted

wherever appropriate. Begin each answer on a fresh sheet of paper

and arrange your answers in numerical order.

Tear off the front page of this question paper in your answer

sheets of Section B, and tie both of them together with your answer

sheets in Section C.

Values of constant are provided.

Answers may be written in either English or Bahasa Malaysia

For examiners use (Untuk kegunaan

pemeriksa)

Section A

(Bahagian A)

Section B

(Bahagian B)

16

17

Section C

(Bahagian C)

Total

(Jumlah)

This question paper consists of 12 printed pages and 0 blank pages.

(Kertas soalan ini terdiri daripada 12 halaman bercetak dan 0 halaman kosong.)

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Answer all questions in this section

1 In discussing electric field, the terms electric field strength, electric potential and

potential gradient are used. Which of the following statements is correct concerning

the terms used?

A A unit potential gradient exists between two points if one joule of work is done to

move one coulomb of charge between the two points.

B Electrical potential at a point is the force exerted on a unit positive charge placed

at the point.

C Electrical potential and potential gradient are scalar quantities.

D The potential gradient at a point is equal to the numerical value of the electric

field strength at the point.

2 Which of the following physical quantities does not have a value of zero on the

surface of an isolated conductor?

A Electric potential at the surface

B Current flowing on the surface

C Magnetic field near the surface

D Electric field along the surface

3 A capacitor with capacitance C is charged to charge Q so that the potential difference

across it is V. Which of the shaded areas in the following graphs represents the

electric energy acquired by the capacitor?

A Q V

B Q C

C V

D Q

4 A parallel plate capacitor is charged in air. The capacitor is later immersed in a liquid

dielectric. Which of the following is true?

Capacitance Potential Difference

A Increases Decreases

B Decreases Increases

C Increases Increases

D Decreases Decreases

Section A [15 marks]

C Q 0 0

0 0

3

5 Two capacitors with capacitance of 4 F and 6 F are connected in parallel. The

arrangement is later connected in series with a third capacitor to produce an effective

capacitance of 5 F. The capacitance for the third capacitor is

A 3 F

B 5 F

C 7 F

D 10 F

6 Which of the following graphs is true of the change in the potential difference V across a copper wire with its electrons moving with drift velocity v? (Assume that the cross-sectional area and the temperature of the wire are uniform) A V v

B V v

C V

D Q

7 A conductor with uniform cross-sectional area A has n free electrons per unit volume.

The electrons have drift velocity v in an electric field E. If e is the electronic charge,

the current density J in the conductor is given by

A Ne

B Nev

C nevA

D nevE

v v 0 0

0 0

4

8 How much current is flowing through one of the 10 resistors?

A 0.8 A B 2.0 A C 1.6 A D 2.4 A

9 A milliammeter with negligible internal resistance and a full scale deflection of 1 mA is

modified for use as a voltmeter with a full scale deflection of 10 V.

The correct modification for the required circuit is

A a resistor of 102 is connected in parallel to the milliammeter.

B a resistor of 103 is connected in parallel to the milliammeter.

C a resistor of 104 is connected in series to the milliammeter.

D a resistor of 105 is connected in series to the milliammeter.

10 Hall effect cannot be used to measure

A the charge density

B the magnetic flux density

C the mass of charge carriers

D the type of charge carriers

11 When a stationary electron is acted upon by a uniform magnetic field, the electron will

A move in a circular path

B move in parabolic path

C not move

D be accelerated in a straight line

12 Which of the following produce voltage or current by self-induction? A High voltage or current produced in a transformer

B High voltage produced in a Van de Graff generator

C High voltage produced when the switch in a solenoid circuit is opened

D Current flows in a copper plate when the plate is oscillating in a magnetic

field.

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13 While a magnet is moved toward the end of a solenoid, a voltage difference is induced between the two ends of the solenoid wire. The voltage difference would be larger if

A the speed of the magnet were increased.

B the solenoid contained more loops (while having the same length).

C The bar magnet produced a stronger magnetic field.

D All of the above statements are true.

E Only two of the above statements are true.

14 A sinusoidal current from an electric source is given by

I = I0 sin t

Which of the following expressions for the current is true when the amplitude and

frequency of the current are increased to twice its initial amplitude and frequency

respectively?

A I = I0 sin 2t

B I = 2I0 sin t

C I = 2I0 sin 2t

D I = 2I0 sin

t

15

The 60 Hz ac source of a series circuit has a voltage amplitude of 120 V. The capacitive and inductive reactances are 890 and 350 , respectively. The resistance is 460 . In Figure above, the capacitance, in F, is closest to: A 3.0 B 5.8 C 8.6 D 12.0 E 18.0

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Section B [15 marks]

Answer all questions in this section

16 An electron is released from rest in a uniform electric field strength of 7.5x104 V m-1. The distance between the points XY is 0.45 m.

- - - - - - - -

X

0.45m

Y

+

+

+

+

+

+

+

+

Figure 1

(a) Find the potential difference between points X and Y.

[2 marks]

(b) Find the change in potential energy of the electron when it moves from point X to point Y.

[2 marks]

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(c) If the speed of the electron at X is 2.0 x 106 m s-1, find the speed of the electron at Y.

[3 marks]

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17 An electric circuit consisting of five resistors and three batteries with negligible internal resistance is shown below.

Figure 2

(a) Calculate the currents I1, I2 and I3.

[6 marks]

(b) Determine the potential difference VAB. [2 marks]

R1= 2.0 A R3= 3.0

I3 I1

I

R5= 4.0

R2= 2.0 R4= 3.0

E1= 8.0V

E2= 4.0V

E3= 10.0V

B

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Section C [30 marks]

Answer any two questions in this section

18 (a) (i) State the laws of electromagnetic induction, and write down an equation

which represents the laws.

[2 marks]

(ii) By using the laws in (a)(i), explain why back e.m.f. is produced in

a coil when an alternating potential difference is connected across

the coil.

[4 marks]

(b) Define self-inductance of a coil, and state its S.I. unit.

[2 marks]

(c) An electric current of 1.5 A flows through a coil P producing a total

magnetic flux of 0.540 Wb in the coil. If a coil Q is brought near coil P, a

total magnetic flux of 0.144 Wb is produced in coil Q.

(i) Calculate the self-inductance of coil P, and find the energy stored in

coil P before coil Q is brought near it.

[3 marks]

(ii) Calculate the mutual inductance of coil P with coil Q.

[2 marks]

(iii) If the current in coil P is reduced uniformly from 1.5A to 0 A in time

0.30 s, what is the induced e.m.f. of coil Q?

[2 marks]

19 (a) Define magnetic flux density in terms of the force on a charge. (2 marks)

(b) There are two situations in which a charged particle in a magnetic field does not experience a magnetic force. State these two situations.

(2 marks)

(c) Figure shows a beam of electrons entering a magnetic field of magnetic flux density 8.4 mT. The electrons are traveling with velocity 3.4 107 m s-1 at right angles to the field.

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Figure 4

Calculate, for the electrons in the field, the magnitude of i) the force on an individual electron.

(2 marks) ii) the acceleration of the electron. .

(1 mark)

iii) calculate the radius of the path of the electrons within the magnetic field. (2 marks)

iv) Sketch the path travelled within and beyond the field.

(2 marks)

(d) Charged particles from the Sun, on approaching the Earth, may become trapped in the Earths magnetic field near the poles, as shown in Figure. This can cause the sky to glow. The phenomenon is called the aurora borealis.

Figure 5

Some of the charged particles travel in a circle of radius 50 km in a region where the magnetic flux density is 6.0 10-5 T.

i) For a charged particle of charge to mass ratio e/m, deduce an expression for

its speed v when traveling in a circle of radius r within a magnetic field of flux density B.

(2 marks)

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ii) Use your answer to (i) and the information about the path of the particles to

show that the charged particles causing the aurora cannot be electrons.

(2 marks)

20 (a) In an AC circuit, the supply voltage is given by

where

V in volt and the current is given by I = 0.480 sin (5000t) where I in ampere and t in second. (i) What is meant by root mean squared (rms) value of the current?

(1 mark)

(ii) Calculate the impedance of the circuit. (2 marks)

(iii) Sketch the phasor diagram for V and I and state the electrical component

either RCL, RC or RL. Give your reason. (3 marks)

(iv) Calculate the instantaneous and maximum power dissipated in the circuit.

(3 marks)

(b) A resistor of 6, a capacitor of 3000 F and an inductor of 5 mH are connected in series. If an AC source of 50 Hz and peak voltage of 240 V is connected to this circuit combination, calculate (i) The total impedance of the circuit.

(3 marks)

(ii) The resonance frequency of the circuit and explain the energy dissipated during the resonance.

(3 marks)

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Values of constants

(Nilai Pemalar)

Acceleration of free fall

Avogadro constant

Boltzmann constant

Gravitational constant

Magnitude of electronic

charge

Mass of the Earth

Mass of the Sun

Molar gas constant

Permeability of free space

Permittivity of free space

Plancks constant

Radius of the Earth

Radius of the Sun Rest mass

of electron

Rest mass of proton

Speed of light in free space

Stefan-Boltzmann constant

Unified atomic mass unit

(Pecutan jatuh bebas)

(Pemalar Avogadro)

(Pemalar Boltzmann)

(Pemalar graviti)

(Magnitud cas elektron)

(Jisim Bumi)

(Jisim Matahari)

(Pemalar gas molar)

(Ketelapan ruang bebas)

(Ketelusan ruang bebas)

(Pemalar Planck)

(Jejari Bumi)

(Jejari Matahari)

(Jisim rehat elektron)

(Jisim rehat proton)

(Laju cahaya dalam ruang bebas)

(Pemalar Stefan-Boltzmann)

(Unit jisim atom bersatu)

g = 9.81 m s-2

NA = 6.02 x 1023

mol-1

k, kB = 1.38 x 10-23

J K-1

G = 6.67 x 10-11

N m2 kg

-2

e = 1.60 x 10-19

C

ME = 5.97 x 1024

kg

MS = 1.99 x 1030

kg

R = 8.31 J K-1

mol-1

0 = 4 x 10-7

H m-1

0 = 8.85 x 10-12

F m-1

= (

)

h = 6.63 x 10-34

J s

RE = 6.38 x 106 m

RS = 6.96 x 108 m

me = 9.11 x 10-31

kg

mp = 1.67 x 10-27

kg

c = 3.00 x 108 m s

-1

= 5.67 x 10-8 W m-2 K-4

u = 1.66 x 10-27

kg