Question

An object is kept at a distance of 15 cm from a convex lens of focal length 10
cm. Calculate the image distance and state the characteristics of the image
formed.

Answer 1

hope it helps..........

Answer 2

Answer:

The image distance is 30cm and the nature of the image is real and enlarged.

Explanation:

To answer this question, we'll use the lens formula. It is given as,

$\frac{1}{f}= \frac{1}{v}- \frac{1}{u}$          (1)

Where,

f=focal length of the lens

v=image distance from the lens

u=object distance from the lens

From the question we have,

The object distance from the lens(u)=-15cm

The focal length of the lens(f)=10cm

We can get the following results by substituting numbers in equation (1):

$\frac{1}{10}= \frac{1}{v}- \frac{1}{-15}$

$\frac{1}{v}=\frac{1}{10}+\frac{1}{-15}$

$\frac{1}{v}=\frac{1}{10}-\frac{1}{15}$

$\frac{1}{v}=\frac{3-2}{30}$

$\frac{1}{v}=\frac{1}{30}$

$v=30\ cm$     (2)

The lens' magnification is expressed as,

$m=\frac{v}{u}$       (3)

We get the following results by plugging the data into equation (3):

$m=\frac{30}{15}$

$m=2$     (4)

Hence, the image distance is 30cm and the nature of the image is real and enlarged.

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