Technical terms related to lens - class-VIII
Description: technical terms related to lens | |
Number of Questions: 17 | |
Created by: Preeti Dasgupta | |
Tags: light : reflection and refraction at spherical surfaces refraction of light light - reflection and refraction light, mirrors and lenses lenses lens refraction through a lens natural phenomena light physics refraction of light at curved surfaces |
Fill in the blank.
The focal length of a lens can be expressed in :
A straight line passing through the two centres of curvature of lens is called
The principal axis is also called _______ of the lens.
Which of the following term is not associated with a lens ?
The value of the focal length of the lens is equal to the value of the image distance when the rays are
Fill in the blanks:
The focal length can be expressed in:
Which of the following term is not associated with a lens?
A thin plano-convex lens acts like concave mirror of focal length $0.2m$ when silvered at its plane surface. Refractive index of the material of lens is $1.5$. Radius of curvature of convex surface of the lens is
A plane-convex lens has a refractive index of 1.6 and a radius of curvature 60 cm. What is the focal length of the lens?
Which statement is correct for a zone plate and a lens?
A small object is placed at a distacne 80 cm to the left of the lens. The position and nature of image formed due to I lens is
A point on the principal axis of a lens, to which light rays parallel to the principal axis converge after passing through the lens, is ............
For which of the following is $f > 0$:
I. Concave mirror
II. Convex mirror
III. Converging lens
Centre point of a lens is called
A convex and a concave lens separated by distance $d$ are then put in contact. The focal length of the combination