Advertisements
Advertisements
प्रश्न
A convex lens forms an image of an object equal to the size of the object. Where is the object placed in front of the lens?
उत्तर
Since an object's size is equal to that of an image, it should be positioned two factors from the lens.
APPEARS IN
संबंधित प्रश्न
The distance between principal focus and optical centre of the lens is _________.
- diameter
- focal length
- principal axis
- optical centre
Define focal length of a divergent lens.
An image formed by a concave ______ cannot be obtained on a screen.
A real image cannot be obtained on a screen.
Which type of lens forms always a virtual image?
Explain why, a stick half immersed in water appears to be bent at the surface. Draw a labelled diagram to illustrate your answer.
Write the new Cartesian sign convention for spherical lenses.
If a spherical lens has a power of, −0.25 D, the focal length of this lens will be :
(a) −4 cm
(b) −400 mm
(c) −4 m
(d) −40 cm
What are the three principal rays that are drawn to construct the ray diagram for the image formed by a lens? Draw diagrams to support your answer.
My grandfather uses a bifocal lens in his spectacle. Explain why.