A thin equiconvex lens is made of glass of refractive index 1.5 and its focal length is 0.2 m, if it acts as a concave lens of 0.5 m focal length when dipped in a liquid, the refractive index of the liquid is ____.
The dispersive power of the material of lens of focal length 20 cm is 0.08. The longitudinal chromatic aberration of the lens is ____.
0.08 cm
0.08/20 cm
1.6 cm
0.16 cm
A diminished virtual image can be formed only in ____.
plane mirror
a concave mirror
a convex mirror
concave-parabolic mirror
Which of the following could not produce a virtual image?
Plane mirror
Convex mirror
Concave mirror
All the above can produce a virtual image
An object tall is placed from a concave spherical mirror which has a radius of curvature of The size of the image is ____.
The focal length of a concave mirror is Where an object be placed so that its image is two times and inverted ____.
75 cm
72 cm
63 cm
50 cm
An object of size is placed in front of a convex mirror of radius of curvature at a distance of The size of the image should be ____.
The field of view is maximum for ____.
plane mirror
concave mirror
convex mirror
cylindrical mirror
The focal length of a concave mirror is f and the distance from the object to the principle focus is x. The ratio of the size of the image to the size of the object is ____.
Image formed by a convex mirror is ____.
virtual
real
enlarged
inverted
In a concave mirror experiment, an object is placed at a distance from the focus and the image is formed at a distance from the focus. The focal length of the mirror would be ____.
A convex mirror is used to form the image of an object. Then which of the following statements is wrong?
The image lies between the pole and the focus
The image is diminished in size
The image is erect
The image is real
Given a point source of light, which of the following can produce a parallel beam of light?
convex mirror
concave mirror
concave lens
The image formed by a convex mirror of focal length is a quarter of the size of the object. The distance of the object from the mirror is ____.
A boy stands straight in front of a mirror at a distance of away from it. He sees his erect image whose height is of his real height. The mirror he is using is ____.
plane mirror
convex mirror
concave mirror
plano-convex mirror
A person sees his virtual image by holding a mirror very close to the face. When he moves the mirror away from his face, the image becomes inverted. What type of mirror he is using?
Plane mirror
Convex mirror
Concave mirror
None of the above
Which one of the following statements is true?
An object situated at the principle focus of a concave lens will have its image formed at infinity
Concave mirror can give diminished virtual image
Given a point source of light, a convex mirror can produce a parallel beam of light
The virtual image formed in a plane mirror can be photographed
The relation between the linear magnifications the object distance and the focal length is ____.
While using an electric bulb, the reflection for street lighting should be
from _____.
concave mirror
convex mirror
cylindrical mirror
parabolic mirror
A concave mirror is used to focus the image of a flower on a nearby well from the flower. If a lateral magnification of is desired, the distance of the flower from the mirror should be ____.
A virtual image larger than the object can be obtained by_____.
concave mirror
convex mirror
plane mirror
concave lens