Question

A convex lens of focal length 10 cm is placed at a distance of 60 cm from a screen. How far from the lens should an object be placed so as to obtain a real image on the screen? Calculate the magnification of the image and what are the characteristics.​

Answer 1

Answer:

Here, the real image is formed on the wall which is at a distance of 12 cm from the convex lens. This means that the distance of image from the convex lens or image distance will be 12 cm. Since a real image is fomred on the right side of the lens, so this image distance will be positive. <br> Now, Image distance,

cm (A real image) <br> Object distance, u=? (To be calculated) <br> Focal length, f=+10 cm (it is convex lens) <br> Putting these values in the lens formula: <br>

<br> We get:

<br>

<br>

<br>

<br> So, Object distance, u=-60 cm <br> Thus, the obect should be place at a distance of 60 cm in front of the convex lens. The minus sign shows that the object is on the left side of the lens.

hope it helps...!!!!