Advertisements
Advertisements
Question
An object is 0.09 m from a magnifying lens and the image is formed 36 cm from the lens. The magnification produced is:
(a) 0.4
(b) 1.4
(c) 4.0
(d) 4.5
Solution
4.0
Magnification is given by:
Magnification (m) =`"distance of image from the lens "/distance of object from the lens`
m `(-36 cm) /(-0.09 m) =(36 cm)/(9cm)` =4
APPEARS IN
RELATED QUESTIONS
Which type of mirror could be used as a dentist's mirror?
The image formed by a concave mirror is real, inverted and of the same size as the object. The position of the object must then be:
(a) at the focus
(b) between the centre of curvature and focus
(c) at the centre of curvature
(d) beyond the centre of curvature
Describe the New Cartesian Sigh Convention used in optics. Draw a labelled diagram to illustrate this sign convention.
If the magnification of a body of size 1 m is 2, what is the size of the image?
What is the nature of image formed by a concave mirror if the magnification produced by the mirror
+4
When an object is placed 20 cm from a concave mirror, a real image magnified three times is formed. Find:
(a) the focal length of the mirror.
(b) Where must the object be placed to give a virtual images three times the height of the object?
One wants to see a magnified image of an object in a mirror. What type of mirror should one use?
To obtain a magnification of, –0.5 with a convex lens, the object should be placed:
(a) at F
(b) between optical centre and F
(c) between F and 2F
(d) beyond 2F
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
A magnifying lens has a focal length of 100 mm. An object whose size is 16 mm is placed at some distance from the lens so that an image is formed at a distance of 25 cm in front of the lens.
Where should the object be placed if the image is to form at infinity?