Question

The focal length of a convex lens is 15 cm. An object is placed at a distance 25cm

away from the optic centre. Calculate the distance of the image from the object. Also

calculate magnification.​

Answer 1

Answer:

50cm

Explanation:

because it is me and I will send you

Answer 2

Given:-

•Focal length of a convex lens is 15cm.

•Object is placed at a distance is 25cm away from the optic centre.

To Find:-

•Calculate the distance of the image from the object.

Solution:-

we have,

• u = 25cm
• f = 15 cm

Using Formula:

$\: \: \sf \: \frac{1}{v} - \frac{1}{u} = \frac{1}{f}$

Now substiute the values,

$\: \: \sf \: \frac{1}{v} - \frac{1}{ - 25} = \frac{1}{15} \\ \\ \: \: \sf \: \frac{1}{v} + \frac{1}{25} = \frac{1}{15 } \\ \\ \: \: \sf \: \frac{1}{v} = \frac{1}{15} - \frac{1}{25} \\ \\ \: \: \sf \: \frac{1}{v} = \frac{1}{60} \\ \\ \: \: \sf \: v = 60cm$

Hence,image distance is 60cm.

Now we are said to magnify

Using Formula:

$\: \: \sf \: m = \frac{height \: of \: image}{height \: of \: object}$

Now substitute the values

$\: \: \sf \: m = \frac{60}{25} = 2.4$

Hence image formed is virtual,eract and magnifing approx two times.

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Extra Info...

• V denotes image distance
• U denotes object distance
• F denotes focal length