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GNP502S-GENERAL PHYSICS 1B - JAN 2020 |
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NAMIBIA UNIVERSITY
OF SCIENCE AND TECHNOLOGY
FACULTY OF HEALTH AND APPLIED SCIENCES
DEPARTMENT OF NATURAL AND APPLIED SCIENCES
QUALIFICATION: BACHELOR OF SCIENCE
QUALIFICATION CODE: 07BOSC
COURSE: GENERAL PHYSICS 1B
LEVEL: 5
COURSE CODE: GNP502S
SESSION: JANUARY 2020
DURATION: 3 Hours
PAPER: THEORY
MARKS: 100
SUPPLEMENTARY/SECOND OPPORTUNITY EXAMINATION QUESTION PAPER
EXAMINER(S) | DR ONJEFU SYLVANUS
MODERATOR: | PROF DIPTI SAHU
1. Answer ALL the questions
2. Write clearly and neatly
3. Number the answers clearly
INSTRUCTIONS
PERMISSIBLE MATERIALS
Non-programmable Calculator
ATTACHMENT
None
THIS QUESTION PAPER CONSISTS OF 6 PAGES
(Including this front page)
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SECTION A
QUESTION 1
[40]
Suggested Question Types: Multiple Choice/Objectives
Each question in this section carries two marks
1.1 The diagram below shows a ray of light IK incident on plane mirror at K.
Calculate the angle of deviation of the ray after reflection.
(2)
35°
7
[77,077
a.35° =b. 70°. 55° d. 90°
1.2 The combination of two overlapping waves is called what?
(2)
a. aggregate
b. superposition
c.dispersion d. wavelength
1.3 A hunter at a distance x from a cliff fires a gun. He hears the echo from the cliff
after 2.4 seconds. If the speed of sound in air is 340 m/s, determine x.
(2)
a. 408 m
b. 209 m
c. 100m
d.501m
1.4 One of these is not a wind instrument.
(2)
a. Clarinets
b. trumpets
c. drums
d. flutes
1.5
A beam of polarized light is one constrained to vibrate in a secese...... plane
perpendicular to the beam.
(2)
a.multiple b.triple c.single —_d. quadruplet
1.6 Sound wave below 20 Hz is called what?
(2)
a. ultrasonic wave
b.audiblewave
cc. infrasonic wave
__d. critical wave
1.7 One of the following is not an example of electromagnetic waves.
(2)
a. beta
b. gamma
c. X rays
d. ultraviolet light
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Questions 1.8 and 1.9 are based on the statement below:
The amplitude modulation (AM) radio band extends from 5.4 x 10° Hz to
1.7 x 10 © Hz. If the speed of light is 3 x10 8 m/s;
1.8
What is the longest wavelength in meters?
a.1.8x102m _ b.5.6x10*m c.6.5x103m d.0.9x103m
1.9 Determine the shortest wavelength.
a.1.8x102m
b.5.6x102m
c.6.5x 103m
d.0.9x103m
1.10 Light reflecting off a flat mirror creates an image that appears to be.............
the mirror.
a. infront
b. behind
c. lateral
d. tangential
1.11 beeseseenee image cannot be projected on a screen.
a. real
b. virtual
c. Critical
d. principal
1.12 A string is stretched rightly between two points 50 cm apart. It is plucked at
its centre and the velocity of the wave produced is 300 m/s. Calculate the
number of vibration made by the string in one second.
(2)
a. 3
b.6
c. 150
d. 300
1.13 A light ray of wavelength 589 nm traveling through air strikes a smooth, flat
slab of crown glass at an angle of 30° to the normal. Determine the angle of
refraction.
a. 18.2°
b. 20.1°
c. 17.2°
d.19.2°
1.14 A type of aberration in which the wavelength is dependent on refraction is
called what?
(2)
a. spherical aberration
c. cubical aberration
b. chromatic aberration
d. sita aberration
1.15 The combination of rays gives rise to ............ ?
a. beam
b. radiation
c. particles
d. incident rays
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seseeateee Is a device that transforms energy into a beam of coherent
monochromatic light.
(2)
a. lasers
b. slit order c. path difference
d. diffraction gating
1.17 Suppose the real depth of a pond is 6 m and its apparent depth is 4.5 m.
The refractive index of the water of the pond is given by?
(2)
a. 1.35
b. 1.36
c. 1.47
d. 1.33
1.18 The change of direction of wave front because of a change in the velocity
of the wave in another medium is called what?
(2)
a. Polarization
b. interference
c. diffraction
d. refraction
1.19 Which of the following statements about images formed by a plane mirror
is false? It is;
a. The same size as the object b.virtual c.enlarged
Bbvinaene is the unit of frequency.
a. decibel
b. meters
c. Hertz
d. seconds
d. lateral inverted
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SECTION B
QUESTION 2
[18]
2.1 A wave is represented by the equation y = 2sin (0.5x — 200t), where all distances
are measured in centimetre and time in seconds. For this wave, calculate its
2.1.1 Wavelength,
(4)
2.1.2 Speed,
(4)
2.1.3 Frequency.
(3)
2.2 Explain the term critical angle.
(3)
2.3 If the angle of incidence for light traveling from air to glass is 45 ° and the
angle of refraction in glass is 28°, Evaluate the refractive index of glass with
respect to air.
(4)
QUESTION 3
[12]
3.1 With the aid of a well labelled diagram illustrate how dispersion can affect
light using a prism. Label colour in order of decreasing wavelength.
(5)
3.2 Describe how a stationary wave is obtained.
(3)
3.3 A ray of light strikes a plane mirror at a glancing angle of 55°. Calculate the
angle between the incident and reflected rays as shown in the diagram below. (4)
L |v
550 |
/
[// TTT
3.4 The velocity of light in air and glass are 3 x 108 m/s and 1.8 x 108 m/s
respectively. Calculate the sine of the angle of incidence that will produce
and angle of refraction of 30° for a ray of light incident on glass.
(4)
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QUESTION 4
[16]
4.1 Illustrate with the aid of a diagram destructive interference.
(3)
4.2 The distance between the two slits is 0.030 mm. The second-order bright
fringe is measured on a viewing screen at an angle of 2.150 from the central
maximum. Evaluate the wavelength of the light in nano meter
(4)
4.3 What is meant by ‘a beam of polarized light?
(2)
4.4
With the aid of well labelled diagrams, illustrate the action of a Polaroid on
beam of sunlight.
(4)
4.5
List three crystals that serve as light polarizing filter.
(3)
QUESTION 5
[14]
5.1 Suppose a stationary siren emits a note of frequency 440 Hz as the train
approaches it with a velocity of 30 m/s. Determine the frequency that is received
on the train. [Take speed of wave to be 331 m/s].
(3)
5.2 Define resonance.
(2)
5.3 Explain the term end correction.
(2)
5.4
If the fundamental frequency of a closed pipe organ on a day when the speed
of sound is 340 m/s is 170 Hz, then the length of the pipe is given as what?
(5)
5.5
Explain why a tuning fork sounds louder when its stem is pressed against a
table top.
(2)
END