IPH402S - INTRODUCTION TO PHYSICS B - 2ND OPP SUPL - JAN 2023


IPH402S - INTRODUCTION TO PHYSICS B - 2ND OPP SUPL - JAN 2023



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nAmlBIA UnlVERSITY
OF SCIEnCE Ano TECHn OLOGY
FACULTY OF ENGINEERING AND THE BUILT ENVIRONMENT
lnSTEM
QUALIFICATION:INTRODUCTION TO SCIENCE,TECHNOLOGY,ENGINEERINGAND MATHEMATICS
QUALIFICATIONCODE: 04STEM
LEVEL: 4
COURSECODE: IPH402S
COURSENAME: INTRODUCTION TO PHYSICSB
SESSION:
JANUARY 2023
PAPER:
N/A
DURATION: 3 HOURS
MARKS:
100
SECOND OPPORTUNITY/SUPPLEMENTARY EXAMINATION QUESTION PAPER
EXAMINER(S)
Ms Ilana Malan
Ms Oksana Kachepa
MODERATOR:
Mr Anthony Apata
INSTRUCTIONS
1. Answer all questions.
2. Write all the answers in ink.
3. No books, notes, correction fluid (Tippex) or cell phones allowed.
4. Pocket calculators are allowed.
5. You are not allowed to borrow or lend any equipment or stationary.
6. Use graph paper for question 14.2
7. All FINALANSWERSmust be rounded off to THREEDECIMALPLACES.
8. All CONSTANTVALUESandFORMULAoSn page 8.
THISQUESTIONPAPERCONSISTSOF 8 PAGES{Excluding this front page)

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SECTION A-TOTAL MARKS 30
This section consists of nine (9) questions. Choose the correct answer and clearly indicate
your answer on your answer sheet. Answer all the questions.
Question 1
[2]
A hiker shouts towards a vertical cliff 550 m away. The echo is heard 3.2 slater. What is
the speed of sound in the air?
(a)
341 m/s
(b)
344 m/s
(c)
333 m/s
(d)
327 m/s
Question 2
[2]
A source of sound approaches observer. The Doppler effect may be described by the
observer as:
(a)
The increase in loudness of the sound.
(b)
The increase in wavelength of the sound.
(c)
The increase in frequency of the sound.
(d)
The increase in relative speed of the sound.
Question 3
[4]
A dolphin click is shown on the oscilloscope screen in Fig. 1 with the time-base division
set at 30 microseconds per division. What is the frequency of these clicks?
(a)
4167 Hz
(b)
2 083 Hz
(c)
8 333 Hz
(d)
17 000 Hz
Fig.1
1

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Question 4
[4]
A body of mass 2 kg and volume 5x10·4 m3 is hung from a balance graduated in Newtons.
What would the balance read when the body is fully immersed in paraffin? Density of
paraffin is 800 kg/m 3•
(a)
15.696 N
(b)
20.399 N
(c)
17.883 N
(d)
14.793 N
Question 5
[4]
A manganin wire of radius 0.15 mm has a resistance of 5.33 O per metre of length.
What is the resistivity of manganin?
(a)
4.895x10·6 Om
(b)
3.768x10·7 Om
(c)
1.118x1Q·8 Om
(d)
2.813x10·7 Om
Question 6
[4]
The total resistance of the circuit show in Fig 2 is:
60 Y
10 n 10 n
(a)
200
(b)
30V
(c)
360
(d)
100
16 11
Fig.2
2

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Question 7
[4]
A transformer outside a house steps the voltage down from Vin = 960 volt. What is the
voltage output of this transformer if the number of primary coils is 80 and the number
of secondary coils is 20.
{a)
480 V
(b)
360V
(c)
120 V
{d)
240 V
Question 8
[4]
If the count rate from a radioactive source is 648 counts per minute and it drops to 81
counts per minute in 45 minutes, what is the half-life of the source?
(a)
450 s
(b)
150 s
{c)
600 s
{d) 900 s
Question 9
[2]
What is the wavelength of light in which the photons have energy of 500 eV?
{a) 2.5 nm
(b) 3.7 nm
{c) 2.8 nm
{d) 6.3 nm
3

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SECTION B -TOTAL MARKS 70
This Section consists of six (6) questions. Answer ALL the questions.
Question 10
10.1 Distinguish between the longitudinal wave and the transverse wave in terms
of the motion of the particles and give one example of each.
(4)
10.2 The Fig. 3 represents the wavefronts spreading out from two coherent sources.
The solid circles indicate the crests of waves and the broken lines indicate the
troughs of waves. State the type of interference observed at points A, Band D. (3)
- - _.A...,-.-_
, , , ~' ~'
',
''
,I
I
;
'
I
,~
',
I
I
'J
'',
D
\\
\\
I
I
Fig.3
10.3 A train passes a stationary student at a constant speed while sounding its whistle.
The frequency of the whistle changes, as measured by the student and these
changes are shown in Fig. 4.
600
590
580
N
:i:
:,., 570
,.,'.J
C:
:,
"7'
560
.Ct l
550
540
530
Time
Fig. 4
10.3.1 Determine the speed of the train.
(4)
10.3.2 Determine the frequency of the whistle heard by the observer on the train.
(2)
4

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2 Pages 11-20

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Question 11
11.1 Using information from Fig.5 determine the following:
11.1.1 The buoyant force acting on the object fully immersed in water.
11.1.2 Volume of the object.
11.1.3 Density of the object.
Archimedes' principle
[17]
(2)
(2)
(2)
. __ \\
,..,,., .
!,'.".
!
!
I
i~
,,,,,=-J
0 2012 Encyc!op.cdi« Brilnnnica, Inc.
Fig.5
2 kg
of water
11.2 A solid cube of wood floats on the 36 cm2 side in the container filled with oil.
Determine the visible height of the cube above the oil surface.
(4)
11.3 Describe an ideal fluid?
(3)
11.4 Blood is flowing through an artery of radius 2 mm at a rate of 40 emfs.
Determine the volume of blood that passesthrough the artery in a period of
24 hours. Expressyour answer in litres.
(4)
5

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Question 12
12.1 The battery with an e.m.f. of 12 V and negligible internal resistance supplies
current to four resistors connected as shown in Fig. 6. Using the Kirchhoff's
laws determine the currents 11,Iiand l3 if:
{10)
a+
b
+
11i
Rl
R2
113
c:,R4 +
V
(9 +
+
R3
C
Fig.6
12.2 Three cells each with an emf of 2 V and each with an internal resistance of 0.15 0,
are connected to three external resistors. The 5 0 and 7 0 are connected in
parallel with each other. The third resistor of 49/30 0 is connected in series to the
two parallel resistors. Determine the total current when:
12.2.1 the cells are connected in series
(2)
12.2.2 the cells are connected in parallel
{3)
6

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Question 13
[12]
13.1 Explain two ways how the current can be induced in the coil.
(2)
13.2 Give three ways in which induced current can be increased.
(2)
13.3 Explain how a transformer works.
(5)
13.4 The turns ratio of a step-down transformer is 6:3 with 600 turns on the secondary
coil. When an AC pd of 50 Vis connected to the primary coil, current of 20 mA
flows in it. Determine current in the secondary coil. State any assumption(s). (3)
Question 14
[9]
Caesium-137 is a radioactive isotope of caesium which is formed by the nuclear fission
of uranium-235. It decays by beta emission.
14.1 If 120 g of Caesium-137 is stored in concrete, how many years will it take for its
mass to decrease to 7.5 g? Show your working using a table.
(4)
14.2 On the graph paper provided draw the decay curve for Caesium-137.
(5)
Question 15
[6]
15.1 Define the work function of a metal.
(2)
15.2 A zinc cathode was illuminated by electromagnetic radiation of wavelength
210 nm. Determine the maximum speed of the emitted electrons.
(4)
7

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LISTOF CONSTANTS:
g = 9.81 m/s 2
density of water= 1000 kg/m 3
density of wood = 530 kg/m 3
density of oil = 950 kg/m 3
density of paraffin= 800 kg/m 3•
speed of sound in the air= 340 m/s
speed of light in vacuum = 3 x 108 m/s
half-life of Caesium-137 = 30 years
mass of electron = 9.1 x 10-31 kg
charge of electron=l.6x10- 19 C
Planck constant= 6.626 x 10-34 Js
work function of Zinc= 4.3 eV
1 eV = 1.6 X 10-19 J
1 ml= 1 cm3
List of equations
v=JA
FB =Wr
A,v, = A,,v2
fu=f(v:u)
R=p- A
L
E =hf =¢+KE
P=F
A
p=- m
V
Q=!_
t
+) fu=f( v_u
C=Q
V
Np : N, = VP: V,
P=pgh
flow rate= -V = Av
t
power= VI
powerP = power,
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