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# We need light

A 1.2 cm long pin is placed perpendicular to the principal axis of a convex mirror of focal length 12cm, at a distance of 8cm apart from it.

a) Find the location of image.
b) Find the height of image.
c) Is the image erect or not?

Note by Mehul Chaturvedi
1 year, 11 months ago

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We have $$\dfrac{1}{-8}+\dfrac{1}{v}=\dfrac{1}{12}$$. Solve this to get $$v=24/5$$. Thus image is located at this distance from mirror. Its height you can find using Magnification formula..and erect/not using convention again. · 1 year, 11 months ago

Yeah thats right @Krishna Ar · 1 year, 11 months ago

Of course it is :P It's basic class 8 physics · 1 year, 11 months ago

Yeah i studied this in class 7th @Krishna Ar · 1 year, 11 months ago

i just wanna refresh my mind · 1 year, 11 months ago

Use mirror formula. $$\dfrac{1}{v}+\dfrac{1}{u}=\dfrac{1}{f}$$ where $$u,v,f$$ stand for object distance, image distance and focal length respectively. Use Cartesian convention to aid with the signs. For convex mirror, find out which is positive and which is not. Then its easy · 1 year, 11 months ago