Advertisements
Advertisements
प्रश्न
In order to obtain a magnification of, –3 (minus 3) with a convex lens, the object should be placed:
(a) between optical centre and F
(b) between F and 2F
(c) at 2F
(d) beyond 2F
उत्तर
Between F and 2F
In the case of a convex lens, for an object placed between F and 2F, the image formed will be real, inverted and enlarged.
APPEARS IN
संबंधित प्रश्न
A student wants to project the image of a candle flame on a screen 90 cm in front of a mirror by keeping the flame at a distance of 15 cm from its pole.
(a) Suggest the type of mirror he should use.
(b) Determine the linear magnification in this case.
(c) Find the distance between the object and its image.
(d) Draw ray diagram to show the image formation in this case
What is the magnification of the images formed by plane mirrors and why?
A dentist's mirror has a radius of curvature of 3 cm. How far must it be placed from a small dental cavity to give a virtual image of the cavity that is magnified five times?
One wants to see a magnified image of an object in a mirror. What type of mirror should one use?
A virtual, erect and magnified image of an object is to be obtained with a convex lens. For this purpose,the object should be placed:
(a) between 2F and infinity
(b) between F and optical centre
(c) between F and 2F
(d) at F
A small object is so placed in front of a convex lens of 5 cm focal length that a virtual image is formed at a distance of 25 cm. Find the magnification.
Linear magnification produced by a convex lens can be:
(a) less than 1 or more than 1
(b) less than 1 or equal to 1
(c) more than 1 or equal to 1
(d) less than 1, equal to 1 or more than 1
If a magnification of, –1 is to be obtained by using a converging lens of focal length 12 cm, then the object must be placed:
(a) within 12 cm
(b) at 24 cm
(c) at 6 cm
(d) beyond 24 cm
In order to obtain a magnification of, –0.75 with a convex lens of focal length 8 cm, the object should be placed:
(a) at less than 8 cm
(b) between 8 cm and 16 cm
(c) beyond 16 cm
(d) at 16 cma
The power of a lens is +4D. Find the focal length of this lens. An object is placed at a distance of 50 cm from the optical centre of this lens. State the nature and magnification of the image formed by the lens and also draw a ray diagram to justify your answer.
