40 cm What is the distance of the final image formed by this lens system 1 120 cm to the right of lens A 2 90 cm to the right of lens A 3 22 5 cm to the right of lens B 4 45 cm to the right of lens B 8 A person can see clearly objects only when they lie between 50 cm and 400 cm from his eyes In order to increase the maximum distance of distinct vision to infinity the type and power of the correcting lens the person has to use will be 1 convex 2 25 diopter 2 concave 0 25 diopter 3 concave 0 2 diopter 4 convex 0 5 diopter 3 54 0 cm 4 37 3 cm 30 cm 10 A concave mirror of the focal length fi is placed at a distance of d from a convex lens of focal length f2 A beam of light coming from infinity and falling on this convex lens concave mirror combination returns to infinity The distance d must be equal 1 f f 7 616 4 2f1 f 9 An astronomical telescope has an objective and eyepiece of 13 focal lengths 40 cm and 4 cm respectively To view an objectThe refracting angle of a prism is A and refractive index of 200 cm away from the objective the lenses must bethe material of the prism is cot A 2 The angle of minimum separated by a distance 1 46 0 cm 2 0 0 cm deviation is 1 180 3A 2 180 2A 3 90 A 4 180 2A 11 You are standing on the shore of a lake You spot a fish swimming below the lake surface You want to kill the fish first by throwing a spear and next by pointing a high power laser torch How should you aim the spear and torch respectively from the options given below I above the apparent position of the fish II below the apparent position of the fish III directly at the apparent position of the fish 1 SPEAR II LASER III 2 SPEAR I LASER II 3 SPEAR II LASER II 4 SPEAR III LASER III 12 A boy is trying to start a fire by focusing sunlight on a piece of paper using an equiconvex lens of focal length 10 cm The diameter of the sun is 1 39 x10 m and its mean distance from the earth is 1 5 x 10 m What is the diameter of the sun s image on the paper 1 9 2 x 104 m 2 6 5 x 10 m 3 6 5 x 10 m 4 12 4 x 10 m 14 In an astronomical telescope in normal adjustment a straight line of length L is drawn on inside part of the objective lens The eye piece forms a real image of this line The length of this image is 1 The magnification of the telescope is 1 4 1