1 |
The speed of light in vacuum is 3 x 108 ms-1.Its speed in a medium of refractive index 1.5 will be |
6.5 x 10<sup>8</sup>
2 x 10<sup>8</sup> ms<sup>-1</sup>
4.5 x 10<sup>8</sup> cm
5.5 x 10<sup>8</sup>
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2 |
The critical angle for a ray of light suffering total internal reflection will be smallest for the ray traveling from |
Water to glass
Water to air
Glass to air
Glass to water
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3 |
Just before setting the sun may appear to be elliptical This happens due to |
Diffraction
Reflection
Dispersion
Refraction
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4 |
At what distance should a book be placed from a 50 Cd bulb so that the luminance on the book becomes 2 Im m-2 |
50 m
10 m
5 m
1 m
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5 |
Inverse square law for luminance is valid for |
Search light
Isotropic point source
Cylindrical source
All types of sources
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6 |
If the distance of a surface from light source is doubled,then the luminance will become |
1/4 times
1/2 times
2 times
4 times
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7 |
A beam of light enters air from water.Which of the following characteristics of light will not change in water? |
Frequency
Wavelength
Velocity
Amplitude
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8 |
For obtaining equal and same height mirror should be |
Convex
Concave
Plane
None
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9 |
In a astronomical telescope the final image for normal vision is formed at |
The focal of the eye piece
The least distance of the distinct vision
The focus of the objective lens
Infinity
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10 |
If the red light is replaced by blue light illuminating the object in a microscope the resolving power of the microscope |
Decreases
Increases
Gets halved
Remains unchanged
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11 |
Near and far points of a healthy human eye respectively are |
0 and 25 cm
0 and infinity
25 cm and 100 cm
25 cm and infinity
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12 |
The resolving power of telescope depends on |
Focal length of eye lens
Focal length of objective lens
Length of the telescope
Diameter of he objective lens
|
13 |
In a compound microscope the intermediate image is |
Virtual erect and magnified
Real,erect and magnified
Virtual,inverted and magnified
Virtual,erect and reduced
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14 |
Resolving power of a telescope depends on: |
The magnification of eyepiece
The focal length of objective lens
Diameter of objective lens
Refractive index of objective lens
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15 |
Geometrical optics cannot give following characteristics for a microscope |
Image position
Image size
Resolution of image
Any of the above
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16 |
While viewing a distant object with a telescope suddenly a housefly sits on objective lens.The correct statement is that |
Housefly will be seen enlarged in image
Housefly will be seen reduced in image
Intensity of image will be decreased
Intensity of image will be increased
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17 |
The astronomical telescope consists of objective and eye piece.The focal length of he objective is |
Equal to that of the eye piece
Greater than that of eye piece
Shorter than that of eye piece
Five times shorter than that of the eye piece
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18 |
For the normal setting of a telescope |
Only the object is at infinity
Only the final image is at infinity
Both the object and the final image is at infinity
Neither the object nor the final image has to be at infinity
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19 |
Which of the following is conserved when light waves interfere? |
Intensity
Energy
Amplitude
Momentum
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20 |
A convex lens has focal length F.An object is placed at P then |
Image is formed at + ∞ and is real
Image is formed at + ∞ and is virtual
Image is formed at + ∞ and is real
Image is formed at + and is virtual
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