light

Th e branch of physics that deals with the properties and applications of light is called
1. ray optics
2. wave optics
3. both
4. none of these
Light falling on any polished surface such as a mirror, is
1. refracted
2. reflected
3. dispersed
4. none of these
Th e angle made by the incident ray with the normal (i = angle AON) is called angle of
1. normal
2. reflection
3. incidence
4. emergence
The angle of incidence is equal to angle of
1. emergence
2. normal
3. reflection
4. refraction
If the light rays coming from an object actually meet, aft er reflection, the image formed will be a .......image and it is always .............
1. virtual , erect
2. real, erect
3. real , inverted
4. none of these
Such mirrors whose refl ecting surfaces are spherical are called
1. parabolic mirror
2. spherical mirrors
3. plane mirror
4. none of these
s the refl ecting surface is curved inwards, that is, it faces towards the centre of the sphere. Th ey are called ............ mirrors.
1. concave
2. convex
3. plane
4. none of these
When the object is far away (at infinity), the rays of light reaching the concave mirror are parallel to each other The image is formed at the
1. principal focus F.
2. Between the principal focus F and centre of curvature C.
3. The image is at the centre of curvature
4. none of these
When the object is at the centre of curvature, the nature of mage is
1. Real, inverted and smaller than object.
2. It is real, inverted and same size as the object.
3. It is real inverted and magnified.
4. The image is behind the mirror.
A ray of light passes from one medium to another medium. Refraction takes place when angle of incidence is
1. 0 $°$
2. 45 $°$
3. 90 $°$
4. none of these
When the object is beyond the centre of curvature the image is at
1. principal focus F.
2. Between the principal focus F and centre of curvature C.
3. The image is at the centre of curvature
4. none of these
The object is always placed on the ............ side of the mirror.
1. right
2. left
3. centre
4. none of these
The principal axis is taken as the ........ of the coordinate system
1. x-axis
2. y -axis
3. x ' -axis
4. y ' - axis
All distances are measured from the ......... of the mirror
1. curvature
2. radius
3. pole
4. none of these
Distances measured in the direction of incident light are taken as ........... and those measured in the opposite direction are taken as ............
1. negative , positive
2. positive , negative
3. both
4. none of these
All distances measured perpendicular to and below the principal axis are considered to .................
1. negative
2. positive
3. neutal
4. none of these
The expression relating the distance of the object (u), distance of the image (v) and the focal length (f) of a spherical mirror is called the..................
1. lens equation
2. bipolar equation
3. mirror equation
4. none of these
A negative sign in the value of magnification indicates that the image is...........
1. virtual
2. real
3. inverted
4. none of these
in reflectors of torch which mirror is used............
1. plane
2. concave
3. convex
4. bifocal lens
astronomical telescopes use ....................
1. convex mirror
2. plane mirror
3. concave mirror
4. none of these
This ability of Some organisms to make their own light is called
1. luminescence
2. trioluminescence
3. bioluminescence
4. none of these
the speed of light in vacuum is known to be almost exactly.............km per second.
1. 300,000
2. 500,000
3. 30,000
4. 400,000
The bending of light rays when they pass obliquely from one medium to another medium is called .......... of light
1. emergence
2. refraction
3. reflection
4. none of these
Velocity of light is more in a .........medium than in a denser medium
1. rarer
2. denser
3. both
4. none of these
When a ray of light travels from optically rarer medium to optically denser medium, ........................
1. it goes straight without any deviation
2. it bends away from the normal.
3. it bends towards the normal.
4. none of these
A ray of light incident normally on a denser medium, ....................
1. it bend towards thenormal
2. goes without any deviation.
3. it bend away the normal
4. none of these
Laws of refraction, also known as ............
1. freuds law
2. gallelio law
3. fizeau law
4. snell's law
when a pencil is put in a beaker it appears The pencil appears to be bent at the surface of water why
1. becauseof emergence of light
2. because of dispersion of light
3. because of reflection of light
4. because of refraction of light
The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant for a light of given colour and for the given pair of media.the constant is called the
1. refractive index
2. mutative index
3. both (a) and (b)
4. none of these
unit of refractive index is
1. cm
2. m
3. newton
4. unitless
When the angle of incidence in the denser medium increases the angle of refraction also increases and it reaches a maximum value of r = 90º for a particular value. Th is angle of incidence is called .............
1. incident angle
2. critical angle
3. emergence angle
4. none of these
When the angle of incidence exceeds the value of critical angle, the refracted ray is not possible the ray is totally reflected back to the same medium. This is called as ..................
1. total internal reflection
2. total external reflection
3. both of these
4. none of these
the cause for the spectacular brilliance of diamonds and twinkling of stars is
1. reflection
2. dispersion
3. total internal reflection
4. none of these
The radius of the hollow sphere of which the spherical mirror forms a part. is called
1. radius of curvature
2. centre of curvature
3. pole
4. none of these
Th e point on the principal axis of the spherical mirror where the rays of light parallel to the principal axis meet or appear to meet aft er refl ection from the spherical mirror is called
1. principle axis
2. principle focus
3. pole
4. aperture

light

Quiz