Convex mirror

Electricity and Magnetism Level 1

As shown above, when an object with a height of $3\text{ cm}$ is placed on the optical axis of a convex mirror at a distance of $12\text{ cm}$ from the mirror, the height of its image is $1\text{ cm}.$ Then what is the focal length of the convex mirror?

6

8

4

2

1 solution

Vasu Goyal
Apr 20, 2014

1/f=1/v=1/u <=>1/f=1/4-1/12=1/6 <=> f=6cm

f/(f-u) =1/3 => f=6

vikas boora - 7 years, 1 month ago

how???? can you please explain me with theory????

Mirtaki Tajwar - 7 years ago

m=height of image / (height of object)=i/o 1/f=1/v+1/u multiply by u we get u/f=u/v+1 (m=-v/u) u/f=-1/m+1 1/m=1-u/f m=f/(f-u)=i/o

akshat trivedi - 7 years ago

Convex mirror

1 solution

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