KnowledgeBoat Logo

Science

The below image shows a thin lens of focal length 5 m.

The below image shows a thin lens of focal length 5 m. CBSE 2024 Science Class 10 Sample Question Paper Solved.

(i) What is the kind of lens shown in the above figure?

(ii) If a real inverted image is to be formed by this lens at a distance of 7 m from the optical centre, then show with calculation where should the object be placed?

(iii) Draw a neatly labelled diagram of the image formation mentioned in (ii).

Refraction Lens

7 Likes

Answer

(i) Convex lens

(ii) Given,

Image distance (v) = 7 m

Focal length (f) = 5 m

Object distance (u) = ?

Using formula,

1f\dfrac{1}{\text{f}} = 1v\dfrac{1}{\text{v}} - 1u\dfrac{1}{\text{u}}

We get,

15\dfrac{1}{\text{5}} = 17\dfrac{1}{\text{7}} - 1u\dfrac{1}{\text{u}}

1u\dfrac{1}{\text{u}} = 17\dfrac{1}{\text{7}} - 15\dfrac{1}{\text{5}} = 5−735\dfrac{5-7}{\text{35}} = −235\dfrac{-2}{\text{35}}

So, u = - 352\dfrac{35}{\text{2}} = -17.5 m

Hence, object should be placed at 17.5 m on the left side of the convex lens.

(iii) Below ray diagram shows the image formation:

The above image shows a thin lens of focal length 5 m. (i) What is the kind of lens shown in the above figure? (ii) If a real inverted image is to be formed by this lens at a distance of 7 m from the optical centre, then show with calculation where should the object be placed? (iii) Draw a neatly labelled diagram of the image formation mentioned in (ii). CBSE 2024 Science Class 10 Sample Question Paper Solved.

Answered By

6 Likes

Related Questions