Question

A concave mirror is having focal length 10 cm. If an object is placed at a distance 5 cm in front of
the mirror, write the nature of the image formed by the mirror.

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Answer 1

Answer:

The nature of image formed by the mirror is real and inverted.

This is because the object placed at between C and F.

Answer 2

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• Mirror is concave.

• Focal length (f) = 10cm

• Object distance (u) = 5cm

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• Nature of image formed.

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Mirror formula ,

$\\ \bigstar \boxed{\sf \: \frac{1}{v} + \frac{1}{u} = \frac{1}{f} }$

Here ,

• u = -5cm (in front of mirror)

• f = -10cm (in front of mirror)

• v (image distance) = ?

Putting values , we get...

$\\ \\ \sf \: \frac{1}{v} = \frac{1}{f} - \frac{1}{u} \\ \\ \\ \sf \: \frac{1}{v} = \frac{1}{( - 10)} - \frac{1}{( - 5) } \\ \\ \\ \sf \: \frac{1}{v} = \frac{ - 1}{10} + \frac{1}{5} \\ \\ \\ \sf \: \frac{1}{v} = \frac{ - 5 + 10}{50} \\ \\ \\ \sf \: \frac{1}{v} = \frac{5}{50} \\ \\ \\ \bf \: \orange{v = 10cm}$

Hence , image is behind the mirror as image distance(v) is positive.

Hence , image is virtual and erect.

Note :-

• We can also directly find out the nature when focal length and object distance(u) is known.

Here , object was placed between focal length and pole . So , image will be virtual , erect and magnified.