1 |
Due to which phenomenon, diamond shrines so brightly. |
Scattering of light
Refraction of light
Dispersion of light
Total internal reflection
|
2 |
For total internal reflection the light rays enter |
From rarer to denser medium
From, denser to rarer medium
Medium of same refractive index
At an angle 90 <sup>o</sup>
|
3 |
What would be the colour of sky n the absence of atmosphere. |
Blue
Indigo
Red
Black
|
4 |
When a light ray enters from air into water then its wavelength. |
Increases
Decreases
Become infinity
Remains constant
|
5 |
Why does a glass plate inside a colorless liquid become invisible |
The colours of both are same
The densities of both are same
Their refractive indices are same
Their refractive indices are different
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6 |
A concave mirror is used to form an image of the sun on a white screen IF the lower half of the mirror were covered with an opaque card the effect on the image on the screen would be. |
Negligible
To make the image less bright than before
To make the upper half of the image disappear
To make the lower half of the image disappear.
|
7 |
Maximum detail of an object can be seen by a microscope when the object is illuminated by light of. |
Longer wavelegth
Shorter wavelength
X -rays
Gama rays
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8 |
A Galilean telescope with objective of coal length 30 cm and eyepiece of focal length.8 cm when focused for infinity has length equal to |
7.5 cm
2.2 cm
38 cm
240 cm
|
9 |
The length of Galilean telescope is given by |
fo + fe
fo- fe
1/fo - 1/fe
1/fo = 1/fe
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10 |
To final image produced by a compound microscope is. |
Real and inverted
Real and erect
Virtual and erect
Virtual and inverted
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11 |
Image formed by a concave lens is. |
Real
Magnified
Virtual
Real and magnified
|
12 |
The ability's of convex lens to produce convergence in a parallel beam is called its. |
Magnification
Focal length
Power
Strength
|
13 |
Which mirror be used for obtaining a parallel beam of light from a small lamp. |
Plane mirror
Convex mirror
Concave mirror
All of these
|
14 |
Which is defined as the ration of image height of the object height. |
Linear magnification
Angular magnification
Magnifying power
Resolution
|
15 |
When we look at the sky during daytime the light that we see is sunlight that has been absorbed and then re radiated in different directions, This process is called. |
Scattering
Diffusion
Mirage
Rainbow
|
16 |
What would be the colour of sky through hour the day .If the earth has no atmosphere. |
Blue
Red
White
Black
|
17 |
When an obliquely falling ray of light enters from one medium ot another it changes its path this phenomenon is called. |
Reflection
Refraction
Diffusion
Diffraction
|
18 |
The band of colours is called. |
Spectrum
Prism
Medley
LASER
|
19 |
The minimum angle of incidence for which total internal reflection can occur is called. |
Right angle
Acute angle
Critical angle
Obtuse angle
|
20 |
Which law states that the angle of incidence equals the angle of refraction. |
Law of reflection
Law of refraction
Snell's law
Hygens's principle
|
21 |
The working principal of a photograph enlarger is basically the same as that of a. |
Camera
Side projection
Microsopce
Telecopse
|
22 |
The image formed by a projector is |
Real, inverted and enlarged
Real, upright and enlarged
Real ,inverted and diminished
Virtual, upright and diminished
|
23 |
An image formed on the film of camera is |
Real , inverted and diminshed
Virtual, inverted and diminshed
Real upright and diminished
Virtual, upright and idminshed
|
24 |
In case of a convex lens, when object is placed at F |
the image is formed beyond 2 F
the image is formed between F and 2 F
No image is formed
the image is formed behind the object
|
25 |
If a single convex lens is placed closed to the eye then it can be used as |
Telescope
Simple microscope
Compound microscope
Opera glass
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26 |
Two convex lenses of equal focal length 'f' are placed in contact, the resultant focal length is |
Zero
1
2f
f/2
|
27 |
A simple astronomical telescope consists of two |
Concave lenses
Convex mirrors
Convex lenses
Plano convex lenses
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28 |
Loss of power is optical fibre result into |
Poor receipt ion of signals
Delay in time for reception of signals
accurate information at the receivers
All of the above
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29 |
To reduce spherical aberration in optical instruments which of the following should be used. |
Plano convex lenses
Concave lenses
Spherical mirrors
Plane mirrors
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30 |
A leser beam may be used to measure very large distance because it is. |
Unidirectional
Cohernet
Monochromatic
Not absorbed
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