Question

An object is placed at a distance of 60cm from a concave mirror of focal length 20 cm
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Answer 1

Answer:

$y25y {?}^{?}$

Answer 2

Given:

$\sf{u=60cm}$

$\sf{f=20cm}$

$\sf{Mirror=Concave}$

To Find:

Image distance(v)

Magnification(m)

Solution:

$\sf{{\dfrac{1}{f}}={\dfrac{1}{v}}+{\dfrac{1}{u}}}$

$\sf{-{\dfrac{1}{20}}={\dfrac{1}{v}}-{\dfrac{1}{60}}}$

$\sf{{\dfrac{1}{v}}=-{\dfrac{1}{20}}+{\dfrac{1}{60}}}$

$\sf{{\dfrac{1}{v}}={\dfrac{-3+1}{60}}}$

$\sf{v=-30cm}$

$\bold{Magnification:}$

$\sf{m=}{\dfrac{-v}{u}}$

$\sf{m=}{\dfrac{-30}{-60}}$

$\sf{m=}{\dfrac{1}{2}}$