Ray diagrams and image positions for lenses
This type of question, asked 4 times: 2023, 2024, 2025, 2026. All 10 questions below, oldest first.
Try each one first, then open its answer.
Question 1
2023
30 (B)Define the following terms in the context of a diverging lens : (i) Principal focus, (ii) Focal length. Draw a labelled ray diagram to illustrate your answer.Question 2
2023
36(a) An object is placed in front of a convex lens of focal length f. If the distance of the object from the lens is 2f, draw a ray diagram to show the formation of the image. Write the value of magnification in this case. (b) A student has focussed the image of a candle flame on a white screen using a convex lens. The situation is as given below : Length of the flame = 2 cm Focal length of the lens = 12 cm Distance of the flame from the lens = 16 cm If the flame is perpendicular to the principal axis of the lens, calculate the values of the following : (i) Distance of the image from the lens (ii) Length of the image formedQuestion 3
2023
30 (b)A convex lens can form a (i) real, inverted and magnified image as well as (ii) virtual, erect and magnified image of an object. If the focal length of the lens is 10 cm, what should be the range of the object distance in both cases ? Draw ray diagrams to justify your answer.Question 4
2024
36(a) Upper half of a convex lens is covered with a black paper. Draw a ray diagram to show the formation of image of an object placed at a distance of 2F from such a lens. Mention the position and nature of the image formed. State the observable difference in the image obtained if the lens is uncovered. Give reason to justify your answer. (b) An object is placed at a distance of 30 cm from the optical centre of a concave lens of focal length 15 cm. Use lens formula to determine the distance of the image from the optical centre of the lens.Question 5
2024
11How will the image formed by a convex lens be affected, if the upper half of the lens is wrapped with a black paper ?Tap an option to check your answer.
Question 6
2024
25The heat produced at a point due to concentration of sunlight by a convex lens burns a paper. (a) Explain why it happens. (b) Name the term (in the context of the lens used) given to the point at which the paper starts burning. What does the bright spot formed on the paper represent ?Question 7
2025
25 (a)Out of the two lenses, one concave and the other convex, state which one will diverge a parallel beam of light falling on it. Draw a ray diagram to show the principal focus of the lens.Question 8
2025
25 (b)A ray of light after refraction from a convex lens emerges parallel to its principal axis. (i) Draw a labelled ray diagram to show it. (ii) In this case, the incident ray before refraction from the lens passes through a point on its principal axis. Name the point.Question 9
2026
30Rays from the sun converge at a point 25 cm behind a convex lens. The distance at which an object be placed in front of the lens to get a virtual image, is :Tap an option to check your answer.
Question 10
2026
33Draw the ray diagram for the image formation by a lens which shows a magnification of .