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sergij07 [2.7K]

2 years ago

10

at what position an object be placed in front of a concave mirror of radius of curvature 40cm so that an erect image of magnific

ation of 3 be produced ?

1 answer:

Thepotemich [5.8K]2 years ago

8 0

C=40cm
f=C/2=40/2=20

m=3

$\\ \sf\longmapsto m=\dfrac{f}{f-u}$

$\\ \sf\longmapsto 3=\dfrac{20}{20-u}$

$\\ \sf\longmapsto 3(20-u)=20$

$\\ \sf\longmapsto 60-3u=20$

$\\ \sf\longmapsto 3u=40$

$\\ \sf\longmapsto u=13.3cm$

m=magnification
f is focal length
C is radius of curvature
u is object distance

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