Tiêu đề Refl. at Plane surface (S.C.Q.).pdf ✅

PHYSICS Q.1 An unnumbered wall clock shows time 04 : 25 : 37, where 1st term represents hours, 2nd represents minutes & the last term represents seconds. What time will its image in a plane mirror show (A) 08 : 35 : 23 (B) 07 : 35 : 23 (C) 07 : 34 : 23 (D) None of these [C] Q.2 The images of clouds and trees in water always less bright than in reality – (A) because water is forming the image dirty (B) because there is an optical illusion due to which the image appears to be less bright (C) because only a portion of the incident light is reflected and quite a large portion goes mid water (D) because air above the surface of water contains a lot of moisture [C] Q.3 When a plane mirror is placed horizontally on level ground at a distance of 60 m from the foot of a tower, the top of the tower and its image in the mirror subtend an angle of 90o at the eye, placed at the mirror itself. The height of the tower is : (A) 30 m (B) 60 m (C) 90 m (D) 120 m [B] Q.4 An object is initially at a distance of 100 cm from a plane mirror. If, the mirror approaches the object at a speed of 5 cm/s. Then after 6 s the distance between the object and its image will be : (A) 60 cm (B) 140 cm (C) 170 cm (D) 150 cm [B] Q.5 A virtual image is formed by a plane mirror, when the pencil of light is incident on the mirror, then the incident pencil on the mirror is. (A) diverging (B) parallel (C) converging (D) all of the above [A] Q.6 Which of the following letters do not surface lateral inversion : (A) HGA (B) HOX (C) VET (D) YUL [B] Q.7 A mirror is inclined at an angle of o with the horizontal. If a ray of light is incident at an angle of incidence o then the reflected ray makes the following angle with the horizontal -     incident ray (A) o (B) 2o (C) 2 o (D) None of these [D] Q.8 A ray of light making an angle 10o with the horizontal is incident on a plane mirror making a angle  with the horizontal. What should be the value of  so that the reflected ray goes vertically upwards - (A) 20o (B) 30o (C) 40o (D) 45o [C] Q.9 Two mirrors are inclined at an angle  as shown in the figure. Light ray is incident parallel to one of the mirrors. The ray will start retracing its path after third reflection if –  (A)  = 45o (B)  = 30o (C)  = 60o (D) All three [B] Q.10 Two mirrors are placed perpendicular to each other. A ray strikes the first mirror and after reflection from the first mirror it falls on the second mirror. The ray after reflection from second mirror will emerge: (A) Perpendicular to the original ray (B) Parallel to the original ray (C) At 45o to the original ray (D) At 60o to the original ray [B]
Q.11 An object is placed between two plane mirrors set at 60o to each other. The maximum number of images seen will be : (A) 2 (B) 3 (C) 5 (D) 6 [C] Q.12 A light ray is incident on a plane mirror at an angle of 30o with the horizontal. At what angle with horizontal must a plane mirror be placed in its path so that it becomes vertically upwards after reflection ? (A) 30o (B) 60o (C) 70o (D) 90o [B] Q.13 Find the angle between two plane mirrors such that a ray of light is incident on the first mirror and parallel to the second is reflected from the second mirror, parallel to the first mirror. (A) 30o (B) 60o (C) 70o (D) 90o [B] Q. 14 Two plane mirrors are parallel to each other and spaced 20 cm apart. An object is kept in between them 15cm from A. Out of the following at which point is an image not formed in mirror A (distance measured from the mirror A). (A) 15 cm (B) 25 cm (C) 45 cm (D) 55 cm Sol. [C] A and B are two plane mirror 15cm 5cm 20cm A O B distance of images distance of images from A mirror from B mirror 15 cm 5cm 25 cm 35 cm 55cm 45cm 65 cm 75 cm +20 +20 +20 Option (C) is correct Q.15 A point source has been placed as shown in the figure. What is the length on the screen that will receive reflected light from the mirror ? H SOURCE H H 2H SCREEN (A) 2 H (B) 3H (C) H (D) None [A] Q.16 A boy of height H is standing in front of mirror, which has been fixed on the ground as shown in figure. What length of his body can the man see in the mirror ? The length of the mirror is (H/2)– L (A) H (B) H2 /(H2 + L2 ) 1/2 (C) Zero (D) 2H2 /L [C] Q.17 A person’s eye level is 1.5 m. He stands in front of 0.3 m long plane mirror which is 0.8m above the ground. The length of the image he sees of himself is – (A) 1.5 m (B) 1.0 m (C) 0.8 m (D) 0.6 m [D] Q.18 A particle is moving in front of a plane mirror as shown in figure. The velocity of image with respect to object is –  v (A) v sin  (B) v cos  (C) 2 v sin  (D) 2 v cos  [C] Q.19 A boy is walking under an inclined mirror at a constant velocity V m/s along the x-axis as shown in figure. If the mirror is inclined at an
angle  with the horizontal then what is the velocity of the image? V X  Y (A) V sin i + V cos j (B) V cos i + V sin j (C) V sin 2i + V cos 2j (D) V cos 2i + V sin 2j [D] Q.20 An object is approaching a plane mirror at 5 cm per second. A stationary observer sees the image. At what speed will the image approach the stationary observer ? (A) 5 cm/second (B) 20 cm/second (C) 10 cm/second (D) 15 cm/second [B] Q.21 A plane mirror is moving with velocity 4 i ˆ + 5 j ˆ + 8 k ˆ . A point object in front of the mirror moves with a velocity 3 i ˆ + 4 j ˆ + 5 k ˆ . Here k ˆ is along the normal to the plane mirror and facing towards the object. The velocity of the image is – (A) –3 i ˆ – 4 j ˆ + 5 k ˆ (B) 3 i ˆ + 4 j ˆ + 11 k ˆ (C) –3 i ˆ – 4 j ˆ + 11 k ˆ (D) 7 i ˆ + 9 j ˆ + 11 k ˆ [B] Q.22 A point object is kept in front of a plane mirror. The plane mirror is doing SHM of amplitude 2 cm. The plane mirror moves along the x-axis and x-axis is normal to the mirror. The amplitude of the mirror is such that the object is always infront of the mirror. The amplitude of SHM of the image is – (A) zero (B) 2 cm (C) 4 cm (D) 1 cm [C] Q.23 Figure below shows two plane mirrors and an object O placed between them. What will be distance of the first three images from the mirror M2 - cm→•cm→    (A) 2 cm, 8 cm, 14 cm (B) 2 cm, 12 cm, 18 cm (C) 2 cm, 18 cm, 22 cm (D) 2 cm, 24 cm, 38 cm [C] Q.24 A point object is placed midway between two plane mirrors distance 'a' apart. The plane mirrors form an infinite number of images due to multiple reflections. The distance between n th order image formed in the two mirrors is - (A) na (B) 2 na (C) 2 na (D) n2 a [B] Q.25 Number of images of an object kept symmetrically between two mirrors inclined at angle 72o, would be- (A) two (B) three (C) six (D) four [D] Q.26 Two plane mirrors are inclined to one another at an angle of 40o. A point object is placed symmetrically in between them. The number of images formed due to reflection at both mirrors is - (A) Infinite (B) 9 (C) 8 (D) 6 [C] Q.27 If an object is placed unsymmetrically between two plane mirrors, inclined at an angle of 72o, then the total number of images formed is - (A) 5 (B) 4 (C) 2 (D) 
[A] Q.28 Two plane mirrors M1 and M2 each have length 1 m and are separated by 1 cm. A ray of light is incident on one end of mirror M1 at angle 45o. How many reflections the ray will have before going from the other end ? M2 45° M1 (A) 50 (B) 51 (C) 100 (D) 101 [D] Q.29 Figure shows a cubical room ABCD with the wall CD as a plane mirror. Each side of the room is 3m. We place a camera at the mid-point of the wall AB. At what distance should the camera be focussed to photograph an object placed at A - A B D C 3 m Camera • (A) 1.5 m (B) 3 m (C) 6 m (D) more than 6 m [D] Q.30 It is necessary to illuminate the bottom of a well by reflected solar beam when the light is incident at an angle of  = 40o to the vertical. At what angle  to the horizontal should a plane mirror be placed ? (A) 70o (B) 20o (C) 50o (D) 40o [A] Q.31 Mark the correct options - (A) If the incident rays are converging, we have a real object (B) If the reflected rays are converging, we have a real image (C) The image of a virtual object is called a virtual image (D) If the image is virtual, the corresponding object is called a virtual object [B] Q.32 A point source of light is placed in front of a plane mirror - (A) All the reflected rays meet at a point when produced backward (B) Only the reflected rays close to the normal meet at a point when produced backward (C) Only the reflected rays making a small angle with the mirror, meet at a point when produced backward (D) Light of different colours make different images [A] Q.33 It is desired to photograph the image of an object placed at a distance 3 m from the plane mirror. The camera, which is at a distance of 4.5 m from the mirror, should be focussed for a distance of - (A) 3 m (B) 4.5 m (C) 6 m (D) 7.5 m [D] Q.34 On reflection from a plane surface, the following gets changed - (A) wavelength (B) frequency (C) speed (D) amplitude [D] Q.35 A wave or a pulse is reflected normally from the surface of a denser medium back into the rarer medium. The phase change caused by the reflection- (A) 0 (B) /2 (C)  (D) 3/2 [C] Q.36 A number of images of a candle flame can be seen in a thick mirror. The brightest image is - (A) The first one (B) The second one (C) The third one (D) The last one [B] Q.37 A lamp and scale arrangement, used to measure small deflection, is shown in the figure. SS' is the glass scale placed at a distance of 1 m from the plane mirror MM and I is the position of the light spot formed after reflection from the undeflected mirror MM. The mirror is deflected by 10o and comes to the deflected position M'M'. The distance moved by the spot on the scale (IR) is –