| 1 |
For single slit diffraction the first minimum occurs when |
dsinθ = <span style="color: rgb(0, 0, 0); font-family: Georgia; font-size: 18px; line-height: 23.390625px;">λ</span>
dsinθ = <span style="color: rgb(0, 0, 0); font-family: Georgia; font-size: 18px; line-height: 23.390625px;">λ</span>/2
dsinθ = 2<span style="color: rgb(0, 0, 0); font-family: Georgia; font-size: 18px; line-height: 23.390625px;">λ</span>
dsinθ = m<span style="color: rgb(0, 0, 0); font-family: Georgia; font-size: 18px; line-height: 23.390625px;">λ</span>
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| 2 |
In Young s experiment the distance between two adjacent fringes for blue light is than that for green light |
Lesser
Greater
Equal
Lesser if distance between source and screen is large
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| 3 |
In electromagnetic waves electric and magnetic field ar |
Parallel
Antiparallel
Perpendicular
Sometimes parallel sometimes perpendicular
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| 4 |
The ratio of fringes with for bright and dark fringes is |
1 : 2
2 : 1
1 : 4
1 : 1
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| 5 |
An oil film floating on water surface show colours due to |
Interference
Diffraction
Scattering
Reflection
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| 6 |
A normal to the waves front showing direction of propagating of wave is called |
Photon
Particle
Ray
Line
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| 7 |
In Young s double slit experiment if we use white light then |
Colored fringes will be observed
Bright fringes will be observed
Alternate dark and bright fringes will be observed
No interference fringes will be seen
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| 8 |
Which one of the following is nearly monochromatic |
Light from candle
Light from simple lamp
Light from sodium lamp
Light from sun
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| 9 |
Polaroid glass is used in sun glasses because |
It is fashionable
It has good color
It is cheaper
It reduces the light intensity to half on account of polarization
|
| 10 |
The phenomenon of diffraction can be exhibited by |
Polarized waves only
Un polarized waves only
Longitudinal waves only
All polarized or un polarized waves and longitudinal or transverse waves
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| 11 |
To observe diffraction phenomenon the size of a obstacle |
Should be much larger than the wavelength
Should be of the same order as the wavelength
Have no relation of wavelength
Should be exactly <span style="color: rgb(0, 0, 0); font-family: Georgia; font-size: 18px; line-height: 23.390625px;">λ/2</span>
|
| 12 |
If Young s double slit experiment is immersed in water then the fringes with |
Decreases
Remains unchanged
Becomes infinite
Increases
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| 13 |
The focal length of the lens of human eye |
Is fixed
Varies from zero to infinity
Can be increased only
Can be decreased only
|
| 14 |
When interference of light takes place |
Energy is created in the region of maximum intensity
Energy is destroyed in region of maximum intensity
Conservation of energy hold goods and energy is redistributed
Conservation of energy does not hold good
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| 15 |
The colour of light is determined by is |
Wavelength
Frequency
Velocity
Amplitude
|
| 16 |
Critical angle of light passing from glass to air is minimum for |
Red
Green
Yellow
Violet
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| 17 |
A completely transparent material will be invisible in vacuum when the refractive index n is |
Unity
More than unity
Less than unity
Equal to 1.33
|
| 18 |
Mirage is a phenomenon due to |
Reflection of light
Refraction of light
Total internal reflection of light
Diffraction of light
|
| 19 |
For incident angles equal or greater than the critical angle the glass air boundary will act as a |
Convex mirror
Concave mirror
Mirror
None if them
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| 20 |
The danger signals are red while the eye is more sensitive to yellow because |
Scattering in yellow colour is less than that of red
Red light is longer in wavelength than yellow light
Scattering in red is less than that of in yellow
Red colour has greater frequency than yellow light
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| 21 |
A driver in a lake wants to signal his distress to a person sitting on the edge of the lake flashing his water proof torch He should direct the beam |
Vertically up wards
Horizontally
At angle to the vertical which is slightly less than the critical angle
At an angle to the vertical which is slightly more than critical angle
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| 22 |
Diffraction of X-ray by crystals show that |
The intensity of X-rays
X-rays have very short wavelength
X-rays are electromagnetic waves
A-rays are just like visible light
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| 23 |
In Michelson interferometer if the moveable mirror is moved through a distance of 8λ then the number of fringes shifted are |
4
8
16
32
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| 24 |
How many fringes will pass a reference point if the moveable mirror of a Michelson s interferometer is moved 0.06 mm The wavelength of light used is 5.89 x10-3 mm |
200
300
20.4
2.3
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| 25 |
Polaroids are used in |
Sun glasses
The production and analysis of plane polarized light
Stereoscopic motion picture
All of these
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| 26 |
Which of the following is an optically active material |
Solution of cane sugar
Liquid nitrogen
Mercury
Polaroid
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| 27 |
Wavelength of a laser beam can be used as a standard of |
Time
Angle
Length
Temperature
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| 28 |
A beam of light of wavelength is incident normally on a grating of element d the angle between the zero-order and first -order spectra depends on |
<span style="color: rgb(0, 0, 0); font-family: Georgia; font-size: 18px; line-height: 23.390625px;">λ </span>only
d only
<span style="color: rgb(0, 0, 0); font-family: Georgia; font-size: 18px; line-height: 23.390625px;">λ </span>and d
<span style="color: rgb(0, 0, 0); font-family: Georgia; font-size: 18px; line-height: 23.390625px;">λ </span>d and distance of screen from the grating
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| 29 |
In a diffraction fringes pattern the fringes are |
Equally spaced
Wider near the centre and narrower away from it
Narrower near the centre and Wider away from it
None of these
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| 30 |
Colour of thin film will not show result from |
Scattering of light
Dispersion of light
Interference of light
Both a and b
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| 31 |
In Young s double slit experiment the separation between the slits in halved and the distance between the slits and the screen is doubled the fringe with will |
Be doubled
Be quadrupled
Remain the same
Be halved
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| 32 |
In an interference fringes pattern the fringes are |
Equally spaced
Wider near the centre and narrower away from it
Narrower near the centre and wider away from it
None of these
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| 33 |
If a point source of light is placed at the focus of a convex lens the rays coming out of the lens will constitute |
Plane wave fronts
Cylindrical wave fronts
Spherical wave fronts
All of above
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| 34 |
Longitudinal waves do not exhibit |
Refraction
Reflection
Diffraction
Polarization
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| 35 |
The wave nature of light was proposed by |
Einstein
Maxwell
Huygen
Newton
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| 36 |
Two sources of waves are called coherent if |
Both have the same amplitude of vibrations
Both produce waves of the same wavelength
Both produce waves of the same wavelength having a constant phase difference
Both produce waves having the same velocity
|