Question 1
Question
What is the phase of electromagnetic wave (E=E0 cos(ωt-kr))?
Question 2
Question
Energy of electromagnetic wave is:
Answer
-
Proportional to cross product of electric and magnetic field vectors
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Proportional to relation of electric field vector to magnetic field vector
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Proportional to the vector addition of electric and magnetic field vectors
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Proportional to dot product of electric and magnetic field vectors
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Proportional to the vector subtraction of electric and magnetic field vectors
Question 3
Question
The speed of light is given by the value of
Question 4
Question
Maxwell’s equation can be written in the form shown below. If magnetic charge exists and if it is conserved, which of these equations will have to be changed?
Question 5
Question
What is the direction of the Poynting vector in the picture
Answer
-
Along negative y axis
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Along positive z axis
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Along positive x axis
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Along negative x axis
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Along negative z axis
Question 6
Question
What is NOT true about electric and magnetic fields?
Answer
-
The electric field and magnetic field each satisfy a wave equation
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The electric and magnetic fields are perpendicular to each other
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The electric and magnetic fields perpendicular to the direction of wave propagation
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The magnitudes of electric and magnetic fields in electromagnetic wave are related by the expression E/B = c
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The electric and magnetic fields does not vary with time for an electromagnetic wave
Question 7
Question
Color of electromagnetic radiation is defined by
Answer
-
Amplitude
-
Frequency
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Phase
-
Speed
-
Intensity
Question 8
Question
What is it visible light?
Answer
-
Electromagnetic waves with wavelengths from 4*10^-7 until 8*10^-7 m in vacuum
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All electromagnetic waves
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Electromagnetic waves with wavelengths from 2*10^-9 until 9*10^-7 m in vacuum
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Electromagnetic waves with wavelengths from 4*10^-7 until 1*10^-3 m in vacuum
-
No right answer
Question 9
Question
Which wave below has the longest wavelength?
Answer
-
Infrared waves
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Radio waves
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Ultra violet waves
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X-rays
Question 10
Question
A sheet of paper will not act as a mirror because paper
Answer
-
Refracts light
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Absorbs light
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Reflects light
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Diffuses light
Question 11
Question
Which of the following is not true about light?
Answer
-
Light needs a medium to travel in
-
The speed of light is different in different media
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Light takes about 8 minutes to travel from the sun to the earth
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It is a form of energy
Question 12
Question
When light reflects from a surface, there is a change in its
Answer
-
Speed
-
Wavelength
-
Frequency
-
All of these
-
None of these
Question 13
Question
Light will almost travel from one place to another along a path of least
Answer
-
Expense
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Distance
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Effort
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Complication
-
Time
Question 14
Question
Which of these electromagnetic waves has the shortest wavelength?
Answer
-
Ultraviolet waves
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Infrared waves
-
Radio waves
-
Light waves
-
X-rays
Question 15
Question
Determining the speed of light became a critical experiment for the wave and particle theories of light because
Answer
-
The wave theory assumes the speed of light is instantaneous
-
Rectilinear propagation only works if the speed of light is very fast
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The wave theory predicted light would move slower in a denser medium, while the particle theory predicted the opposite
-
The particle theory predicted light would move slower in a denser medium, while the wave theory predicted the opposite
Question 16
Question
Which experiment is it? The speed of light was eventually measured when astronomer measured the time it took light to travel from planet to Earth.
Answer
-
Galileo’s experiment
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Roemer’s experiment
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Fizeau’s experiment
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Kepler’s experiment
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Newton’s experiment
Question 17
Question
A spherical, concave mirror is shown in the figure above. The focal point F and the location of the object O are indicated. At what point will the image located?
Question 18
Question
In which figure ray for converging lens is drawn correctly?
Answer
-
a and b
-
a and c
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Only a
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Only b
-
No right answer
Question 19
Question
If the incident ray is precisely at the critical angle, the refracted ray is ______ to the boundary at the point of incidence.
Answer
-
Tangent
-
Normal
-
Sine curve
-
Cosine curve
Question 20
Question
Rainbow appears because of
Answer
-
Refraction and dispersion of sun rays in rain drops
-
Diffraction of sun rays in rain drops
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Reflection of sun rays from rain drops
-
Refraction and dispersion of sun rays in snowflake
-
Interference of sun rays with each other
Question 21
Question
In order to observe interference in light waves, the following conditions must be met:
Answer
-
Source must be coherent
-
Source must be of single wavelength
-
Path difference does not depend on phase difference
-
Amplitude of the two waves should be the same
-
Wavelength and size of slit should be of same order
Question 22
Question
Wave interference can be constructive if
Question 23
Question
Increasing the wavelengths in a double-slit experiment has what effect on the position of maxima on a screen at fixed distance?
Answer
-
None
-
Maxima get closer together
-
Maxima get farther apart
-
Maxima get cancelled by minima
-
Maxima pass minima on the screen
Question 24
Question
In a single slit diffraction experiment, the width of the slit through which light passes is increased. What happens to the central bright fringe?
Question 25
Question
Match every formula with its description:
1) dsinθ = mλ
2) dsinθ = (m + 1/2)λ
Answer
-
1 - Constructive interference for double-slit experiment
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1 - Destructive interference for double-slit experiment
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2 - Constructive interference for double-slit experiment
-
2 - Destructive interference for double-slit experiment
Question 26
Question
Match every formula with its description:
1) 2t = (m + 1/2)λn
2) 2t = mλn
Answer
-
1 - Destructive interference in thin films
-
1 - Constructive interference in thin films
-
2 - Destructive interference in thin films
-
2 - Constructive interference in thin films
Question 27
Question
Match figures of diffraction patterns of two points sources with their description:
Answer
-
A - Patterns are well resolved
-
B - Patterns are well resolved
-
B - Patterns are just resolved
-
A - Patterns are just resolved
Question 28
Question
What is not true about the Fresnel diffraction?
Answer
-
Diffraction is occurring near the aperture
-
a/R ≥ 1, if a is size of aperture, R is distance between aperture and observation points
-
Intensity distribution of Fresnel diffraction
-
In Fresnel diffraction, distance between n-th zone and observation points P is equal to b + n(λ/2), where b is distance between source and point P
Question 29
Question
What is false about doing a double-slit experiment with sound and light:
Answer
-
The sources must be coherent for the interference pattern to be observed
-
They both produce a pattern of high and low intensity (loud and quiet) at some distance away from the double-slit
-
They both work best with a single-frequency source
-
The slits for sound must be extremely close together when compared to light
Question 30
Question
Transmitted light has maximum intensity if transmission axes of polaroids are
Answer
-
Aligned with each other
-
At an angle of 45 degree with each other
-
Perpendicular to each other
-
Optical active and at angle of 30 degree with each other
Question 31
Question
What is true about the polarizing angle?
Answer
-
The angle of incidence at which this polarization occurs
-
The angle of reflection at which this polarization occurs
-
The polarizing angle is called Brewster’s angle
-
The polarizing angle can be defined by Malus’s law
Question 32
Question
Light from any ordinary source (such as a flame) is usually:
Answer
-
Plane polarized
-
Circularly polarized
-
Unpolarized
-
Elliptically polarized
-
Monochromatic
Question 33
Question
The SI standard of time is based on
Answer
-
The daily rotation of the earth
-
The frequency of light emitted by Kr86
-
The yearly revolution of the earth about the sun
-
None of these
Question 34
Answer
-
10^9s
-
10^-9 s
-
10^-10 s
-
10^-11 s
-
10^-16 s
Question 35
Question
The SI standard of length is based on:
Answer
-
The distance from the north pole to the equator along a meridian passing through Paris
-
Wavelength of light emitted by Hg198
-
Wavelength of light emitted by Kr86
-
A precision meter stick in Paris
-
The speed of light
Question 36
Question
Which of the following is closest to a yard in length?
Question 37
Question
There is no SI base unit for area because
Answer
-
We live in a three (not a two) dimensional world
-
An area has no thickness; hence no physical standard can be built
-
It is impossible to express square feet in terms of meters
-
Area can be expressed in terms of square meters
-
Area is not an important physical quantity
Question 38
Question
The SI base unit for mass is:
Answer
-
gram
-
pound
-
kilogram
-
ounce
-
kilopound
Question 39
Answer
-
10^-3 kg
-
10^−6 kg
-
1 kg
-
103 kg
-
106 kg
Question 40
Question
Which of the following weighs about a pound?
Answer
-
0.05 kg
-
0.5 kg
-
5 kg
-
50 kg
-
500 kg