Question

Answer the following.

An object is placed at 50 cm in front of a concave mirror of focal length 20 cm. State the nature and size of the image relative to that of the object.​

Answer 1

Answer:

First of all we find out the position of the image which is given by the image distance v. <br> Here, Object distance, u

cm (It is to the left of lens) <br> Image distance, v=? (To be calculated) <br> Focal length, f

(It is concave lens) <br> Putting these values in the lens formula: <br>

<br> we get,

<br> or

<br> or

<br> or

<br> or

<br> or

<br> So, Image distance,

cm <br> Thus, the image is formed at a distance of 14.3cm from the concave lens. The minus sign for image distance shows that the image is formed on the left side of the concave lens. We know that a concave lens always forms a virtul and erect image, so the nature of image is virtual and erect