Physics-DPP-1-13.Ray Optics

PHYSICS Topic: RAY OPTICS Date: 1. Two plane mirrors are inclined at 70º. A ray incident on one mirror at angle θ after reflection falls on the second mirror and is reflected from there parallel to the first mirror, θ is : (a) 50º (b) 45º (c) 30º (d) 55º 2. Two mirrors labelled L1 for left mirror and L2 for right mirror in the figure are parallel to each other and 3.0 m apart. A person standing 1.0 m from the right mirror (L2) looks into this mirror and sees a series of images. The second nearest image seen in the right mirror is situated at a distance : (a) 2.0 m from the person (b) 4.0 m from the person (c) 6.0 m from the person (d) 8.0 m from the person. 3. A concave mirror is used to form image of the Sun on a white screen. If the lower half of the mirror were covered with an opaque card, the effect on the image on the screen would be (a) negligible (b) to make the image less bright than before (c) to make the upper half of the image disappear (d) to make the lower half of the image disappear 4. A point object is between the Pole and Focus of a concave mirror, and moving away from the mirror with a constant speed. Then, the velocity of the image is : (a) away from mirror and increasing in magnitude (b) towards mirror and increasing in magnitude (c) away from mirror and decreasing in magnitude (d) towards mirror and decreasing in magnitude 5. A concave mirror forms a real image three times larger than the object on a screen. Object and screen are moved until the image becomes twice the size of object. If the shift of object is 6 cm. The shift of the screen & focal length of mirror are (a) 36 cm, 36cm (b) 36cm, 16cm (c) 72cm, 36cm (d) none of these 6. An object is placed infront of a concave mirror of focal length f. A virtual image is formed with a magnification of 2. To obtain a real image of same magnitication, the object has to moved by a distance : (a) f (b) f / 2 (c) 3 f / 2 (d) 2 f /3 7. An object is placed at a distance 2f from the pole of a curved mirror of focal length f (a) The linear magnification is 1 for both types of curved mirror (b) The linear magnification is 1 for a concave mirror 1 (c) The linear magnification is 3 for a convex mirror (d) Both (b) and (c) 8. A short linear object of length b lies along the axis of a concave mirror of focal length f, at a distance u from the mirror. The size of image approximately is 1 æu – f æ f ö æ ö2 (a) bç ö÷2 (b) bç ÷ (c) bæçu – f ö÷ (d) bç f ÷ f ÷ çèu – f ÷ ç ÷ ç ÷ ø ø è f ø èu – f ø PHYSICS Topic: RAY OPTICS Date: 9. A thin rod of length 1 f 3 is placed along the optic axis of a concave mirror of focal length f such that its image which is real and elongated just touches the rod. The magnification is (a) 4 3 (b) 5 3 (c) 3 2 (d) None of these 10. A slab of glass of thickness 3 cm and refractive index 3 2 is placed with its face perpendicular to the principal axis of the concave mirror. If the radius of mirror is 10 cm, the distance at which an object must be placed from the mirror so that the image coincides with the object is (a) 9 cm (b) 10 cm (c) 11 cm (d) 12 cm

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