Question 1 :
Focal length of a lens is 50 cm. Its power would be :
Question 2 :
Where should the object be placed in front of a concave mirror so that the image formed is of the same size as the object?
Question 3 :
Which of the following are common to images formed by both Concave and Convex lens ?
Question 4 :
Due to refraction, sunrise appears ______ sun comes to horizon and sunset appears______sun leaves horizon respectively.
Question 5 :
When a ray of light passes from an optically less dense medium to a more dense medium, it :
Question 6 :
The mirror which always produces an erect and virtual image of a real object is:<br/>
Question 8 :
A plane glass plate is placed over a various coloured letters (violet, green, yellow, red). The letter which appears to raised more
Question 9 :
If the magnification of a body of size 1 m is 2, what is the size of the image?
Question 11 :
Magnification is 0.5 when the object distance is 10 cm. Find the power of the concave lens :
Question 12 :
Four students perform an experiment on tracing the path of a ray of light passing through a rectangular glass slab. Their individual observations are:<br>identify the incorrect observation and correct them.<br>
Question 13 :
A light ray travels at some angle (not head on) from water in a rectangular aquarium, through the glass side, and out into air . The indices if refraction for water, glass, and air are 1.33, about 1.6, and 1.0, respectively.<br/>Rank the material;s according to the angles of refraction  made by the light ray with the normal in each, greatest first.
Question 14 :
What is the nature of image formed by Concave lens ?
Question 15 :
What is the angle of incidence when a ray of light incident on a concave mirror from its centre of curvature?
Question 16 :
If the refractive index of medium $b$ with respect to medium $a$ and that of medium $c$ with respect to medium b are given, then the refractive index of a medium $c$ with respect to a medium $a$ can be found by using the relation<br/>$n_{ca}\, =\, n_{ba}\, \times\, ........$<br/><br/>
Question 17 :
The focal length of a combination of lenses formed with lenses having powers of $+2.50\ D$ and $-3.75\ D$ will be
Question 18 :
Find the power (with sign) of a concave lens of focal length $20cm$.<br/>
Question 20 :
The focal length of a convex lens is $5\,cm$,where should the object be placed to get  a real image with same size as that of object:
Question 21 :
The power of a lens having a focal length of $1 cm$ is :<br/>
Question 24 :
A convex lens is used to form real image of an object on a screen. It is observed that even when the positions of the object and that screen are fixed are two position of the lens to form real images. If the heights of the images are $4\ cm$ and $9\ cm$ respectively the height of the object is
Question 25 :
What is the power of the lens, if the far point of a short sighted eye is $200\ cm$?
Question 26 :
"Value of refractive index remains same for light rays with different wavelength and for a particular material"
Question 27 :
A convex lens makes a real image $4\ cm$ long on a screen. When the lens is shifted to a new position without disturbing the object, we again get a real image on the screen which is $16\ cm$ tall. The length of the object must be
Question 28 :
The constant ratio of the sine of angle of incidence to the sine of angle of refraction is also known as:
Question 29 :
A thin convex lens of focal length $10\ cm$ is placed in contact with a concave lens of same material and of same focal length. he focal length of combination will be
Question 32 :
If $f$ is focal length of the lens in $cm$, then the power of a lens is equal to:
Question 33 :
State whether given statement is True or False<br/>A ray of light incident parallel to the principal axis of a lens, passes undeviated after refraction.<br/>
Question 34 :
When light is refracted from a surface, which of its following physical parameters does not change?
Question 35 :
Two thin lenses of focal lengths $f_{1} and f_{2}$ are in contact and coaxial. The power of the combination is :<br/>
Question 36 :
Find the focal length of a convex lens, if its power is +2.0 D.
Question 37 :
Height of the image of an object on an principal axis produced by a convex lens is double the focal length of lens is $20 cm$, then image distance from the lens is:
Question 38 :
In case of a virtual and erect image, the magnification created by the mirror is
Question 39 :
A ray of light is incident on the surface of transparent medium at an angle of $45^o$ and is refracted in the medium at an angle of $30^o$. What will be the velocity of light in the transparent medium ? <br/>
Question 40 :
The power of a lens having a focal length of $1\;cm$ is :
Question 42 :
Which of the following lens is used to minimise myopia ?
Question 45 :
Which of the following observations cannot be explained by Tyndall Effect?
Question 47 :
Which of the following phenomena contributes significantly to the reddish appearance of the sun at sunrise or sunset?<br/>
Question 48 :
As the thickness of the atmosphere increases colour of scattered light is found in ________order.
Question 49 :
When Astronauts fly at higher altitude, the sky appears dark because ;
Question 50 :
The least distance of distinct vision for a defective eye is $75$ cm. What should be the focal length of the lens which will be used to read a book clearly at $25$ cm?
Question 51 :
The inability among the elderly to see nearby objects clearly because of the weaking of the ciliary muscles is called
Question 52 :
The path of beam of light becomes _____ in a colloidal solution.
Question 53 :
Why do high rise buildings have a red light on the top of the building?
Question 55 :
A defect of vision caused due to excessive curvature of the cornea is:
Question 56 :
An astronaut in a spaceship the sky appears black due to:
Question 57 :
Why are red coloured lights are used in traffic signals to stop the vehicles?
Question 58 :
Intensity of light ray in a directionafter scattering by small particles (smaller than wavelength):
Question 59 :
For the angle of minimum deviation of a prism to be equal to its refracting angle, the prism must be made of a material whose refractive index lies between:
Question 61 :
Long-sightedness is caused by the eyeball being too short. It can be corrected by the use of a :
Question 68 :
CV Raman got the Nobel Prize for his experiment on :
Question 69 :
State whether true or false :Myopia is caused due to the high converging power of the eye lens.
Question 70 :
On passing white light through a glass prism. Whichcolour ray will deviate maximum towards its base?
Question 72 :
The path of a beam of light is invisible in which solution?
Question 79 :
The sun appears red at the time of sun-rise and sun-set. This is because:
