Question 2 :
A prism is a piece of transparent material having _____ triangular and _____ rectangular surfaces.
Question 3 :
At which place in eye,image is formed of a person is far-sightedness (hypermetropia) ?
Question 4 :
An astronaut in a spaceship the sky appears black due to:
Question 5 :
Why astronauts see dark sky in space unlike blue sky on earth:
Question 8 :
Fine beam of light entering through a small hole in a dark room illuminates the particles in its path. Identify the effect associated with this process.<br/>
Question 9 :
The rising and setting of sun appear red because of : 
Question 11 :
Why do high rise buildings have a red light on the top of the building?
Question 12 :
The band of colours obtained on a screen on passing white light through a prism is called :
Question 14 :
A disease, in which eye lens become cloudy and the opaque lens is removed and a new artificial lens is inserted, is :
Question 15 :
The path of a beam of light is invisible in which solution?
Question 16 :
Braille writer slate and stylus is a type of resource for blind people that is called tactual aid
Question 19 :
What is the time difference between actual sunset and apparent sunset?
Question 21 :
A defect of vision caused due to excessive curvature of the cornea is:
Question 24 :
At sun rise of sunset, the sun looks more red than at mid-day because
Question 26 :
When a ray of light passes from an optically less dense medium to a more dense medium, it :
Question 27 :
A person uses spectacles of power $+2\ D$. He is suffering from
Question 28 :
State whether true or false.<br/>A convex mirror always forms a real image.
Question 29 :
The maximum magnification that can be obtained with a convex lens of focal length $2.5\ cm$ is ( the least distance of distinct vision is $25\ cm$)
Question 30 :
A symmetric double convex lens is cut in two equal parts by a plane perpendicular to the principal axis. If the power of the original lens is $4 D$, the power of cut lens will be ________.
Question 31 :
Which of the following is not a characteristic of image formed by Concave lens ?
Question 32 :
Assertion: If refractive index of one medium is equal to refractive index of second medium, then beam does not bend at all.
Reason: The bending of light does not depend on refractive indices of media.
Question 33 :
When the face is very close to the spoon the image formed by the outside bulged part?
Question 35 :
$ \dfrac{\sin i}{\sin r}  =$constant, the value of constant depends upon<br/>a) Pair of media <br/>b) Color of incident light<br/>c) Wave length <br/>d) Refracting nature of material<br/>
Question 37 :
The focal length of a combination of lenses formed with lenses having powers of $+2.50\ D$ and $-3.75\ D$ will be
Question 38 :
A converging lens has a focal length of $50 cm$. The power of the lens is
Question 39 :
Which of the following term is not associated with a lens?
Question 40 :
Due to refraction, sunrise appears ______ sun comes to horizon and sunset appears______sun leaves horizon respectively.
Question 41 :
The power of a lens being $+4$ dioptres suggests that it is a
Question 42 :
When a ray of light passes through a rectangular glass slab, the angle of emergence
Question 43 :
In passing through a boundary, refraction will not take place if
Question 44 :
A ray of light travelling in air is incident on the plane of a transparent medium. The angle of incident is $45^0$ and that of refraction is $30^0$. The refractive index of the medium with respect to air is:
Question 45 :
The frequency of a light wave in a material is $2\times 10^{14} Hz$ and wavelength is $5000\overset {\circ}{A}$. The refractive index of material will be :
Question 47 :
A ray of light passing through the .......... of the lens, passes on undeviated.
Question 48 :
To observe the hydra bud clearly. Raju should see it first under the low power lens and then under the high power lens in order to see 
Question 49 :
State whether true or false.<br/>A concave mirror always forms erect and diminished images.
Question 50 :
Fill in the blank. A _____ is a piece of transparent glass bounded by two spherical surfaces. 
