Question

If an object is placed at a distance of 10 cm in front of a concave mirror of focal length 4 cm, find the position and characteristics of the image formed. Also, find the magnification.

Answers

  1. Answer:

    Explanation:

    Focal length f = – 4 cm

    Object distance u = – 10 cm

    v , image distance = ?

    Mirror formula

    \frac{1}{v} +\frac{1}{u} = \frac{1}{f}

    Putting the given values

    \frac{1}{v} - \frac{1}{10} = - \frac{1}{4}

    \frac{1}{v}= - \frac{3}{20}

    v = – 6.67 cm .

    magnification

    m = v / u

    = – 6.67 / – 10

    = .667

    so image will be smaller in size in comparison with size of object .

    Characteristics will be that ,

    1 ) it will be inverted and

    2 ) it will be real image .

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