Q2 of 38 Page 79

A 10 mm long awl pin is placed vertically in front of a concave mirror. A 5 mm long image of the awl pin is formed at 30 cm in front of the mirror. The focal length of this mirror is

The magnification is given by:




On calculating, we get u= -60 cm


Now, on applying the mirror formula, we get







Thus, the focal length is, F = -20 cm

More from this chapter

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1

Which of the following can make a parallel beam of light when light from a point source is incident on it?

 3

Under which of the following conditions a concave mirror can form an image larger than the actual object?

 4

Figure 10.1 shows a ray of light as it travels from medium A to medium B. Refractive index of the medium B relative to medium A is


(a)


B.


C. 1/


D.

5

A light ray enters from medium A to medium B as shown in Figure 10.2. The refractive index of medium B relative to A will be