Q4 of 45 Page 304

An object of 5cm tall is placed at a distance of 10cm from a concave mirror of radius of curvature 30cm

i) Find the nature, position and size of the image


ii) Draw the ray diagram to represent the above case.


Given,


Height of object (ho) = 5cm


Object length (u) = -10cm


Radius of curvature (R) =-30 cm


The focal length of the mirror is given by,





According to mirror formula,







Hence, the image formed is virtual and behind the mirror.


The magnification is given by



And the magnification is also given by





So, the image formed is magnified and erect.


ii) The figure below is the ray diagram of the above case



• C=Centre of curvature


• F=Focus


• f=Focal length


• u=Object length


• v=Image length


• AB=Object height


• A’B’=Image height


More from this chapter

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1

The refractive index of diamond is 2.42. What is the meaning of this statement inrelation to the speed of light?

 2

i) Redraw the diagram.


ii) This diagram represents _________


iii) Label the parts of the diagram.


iv) Mention the principle used in the device denoted bythis diagram.


 3

i) Find the nature, position and magnification of the image formed by a convex lens of focal length 10cm, if the object is placed at a distance of a) 15cm b) 8cm

ii) Which of the above represents the use of convex lens in a) A film projector


b) The magnifying glass used by palm reader


 5

The optical prescription of a pair of spectacle is

Right eye: - 3.5 D Left eye: - 4.00 D


i) Name the defect of the eye


ii) Are these lenses thinner at the middle or at the edges?


iii) Which lens has a greater focal length?