Advertisements
Advertisements
प्रश्न
State the condition of the following:
A lens has both its focal lengths equal.
Advertisements
उत्तर
If the medium on both sides of the lens is same, the first and second focal lengths are equal.
APPEARS IN
संबंधित प्रश्न
A ray of light after refraction through a lens emerges parallel to the principal axis of the lens. The incident ray either passes through ______.
Distinguish between a real and a virtual image.
Fig shows an object PQ placed on the principle axis of a lens L. The two foci of the kens are F1 and f2. The image formed by the lens is erect, Virtual and dimnished.
(i) Draw the outline ofthe lens L used and Named it.
(ii) Draw a ray of light starting from Q and passing through O. show the same ray after refraction by the lens.
(iii) Draw another ray from Q Which is incident parallel to the principle axis and show how it emerges after refraction from the lens.
(iv) Locate the final image formed.
(a) Draw a sketch to show how a lens is able to produce an image of the sun on a paper screen.
(b)(i) Would you regard the rays from the sun as being divergent, parallel or convergent?
(ii) What is the name given to the point where such rays meet after they have passed through the lens?
(iii) How does the image of the sun sometimes burn a paper screen?
How will you differentiate between a convex and a concave lens by looking at a distant object.
Name the subjective property of light related to its wavelength.
When does a ray of light falling on a lens pass through it undeviated?
Complete the following diagram and state what happens to the ray of light after refraction through the lens.
Complete the following diagram and state what happens to the ray of light after refraction through the lens.
Complete the following diagram and state what happens to the ray of light after refraction through the lens.
