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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 501. |
Which lens bends a light ray more the one having shorter or longer focal length? |
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Answer» The lens with the shorter focal length bends the light more. |
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| 502. |
Name the type of mirror used in the following situations: (i) Rear view mirror in vehicles (ii) Solar furnace (iii) Torch (iv) Solar cooker (v) To get the full length image of tall building. |
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Answer» (i) Rear view mirror in vehicles – convex mirror as it gives virtual image, diminished and cover the wider view. (ii) Solar furnace – concave mirror to concentrate all parallel beam of light. (iii) Torch – concave mirror is used to reflect light rays as parallel beam. (iv) Solar cooker – concave mirror is used to concentrate the heat rays at a point. (v) Convex mirror is used to view a full length tall building. |
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| 503. |
Define magnification of lens. |
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Answer» Magnification (m) = \(\frac { Height if image (h)' }{ Height of object (h) }\) = \(\frac { v }{ u }\) For convex lens ‘m’ can be more than, less than or equal to one. For concave lens ‘m’ is less than one. |
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| 504. |
According to the laws of reflection,A. the angle of incidence (i) = the angle of reflection (r).B. the incident ray, the reflected ray and the normal lie in the same plane.C. the incident ray and the reflected ray lie on either side of the normal.D. All the above. |
| Answer» Correct Answer - B | |
| 505. |
The line joining the centre of curvature and pole of the mirror is called. ______.A. the principal axisB. y-axisC. the centre axisD. None of these |
| Answer» Correct Answer - A | |
| 506. |
What is the magnification of a plane mirror? |
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Answer» m = +1 is the magnification of a plane mirror. |
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| 507. |
One lumen = ______ candle power.A. `10.76`B. `12.56`C. 700D. None of these |
| Answer» Correct Answer - B | |
| 508. |
Write the following steps in sequential order to determine nature of the image formed by a concave mirror where an object is placed at the centre of curvature with the help of a ray diagram. (A) Mark the position of the object infornt of the mirror at the centre of curvature. (B) Draw a diagram, which represents a concave mirror. (C) Draw two lines one passing through F and another line parallel to the principal axis and draw the path of the reflected rays. (D) Draw the principal axis and mark the centre of curvature and principal focus. (E) Mark the position of the image and study its nature.A. BDACEB. BCADEC. ABDCED. ABCDE |
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Answer» Correct Answer - A Initially the diagram of a concave mirror is drawn (B). The principal axis is drawn. The centre curvature and principal focus are marked (D). The object is placed on the principal focus (A) and a light ray traveling parallel to the principal axis and another passing through the principal focus are drawn. Now the path of the corresponding reflected rays are drawn and at the point of intersection of these rays the position of the image is marked (C). The nature of the image is studied E. |
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| 509. |
An object is placed in front of a mirror. Arrange the following steps in sequential order to determine the nature of the mirror. (A) Check whether the image formed is virtual or real. (B) Check whether the virtual image formed is dimished, magnified or same size as that of the object. (C) If the image formed is real, the mirror used is concave. (D) If a magnified vritual image is formed, the mirror is concave, if a dimished virtual image is formed, the morror is convex and if size of the image is equal to the size of the object, plane mirror is used.A. ACBDB. BDCAC. ACDBD. BADC |
| Answer» Correct Answer - A | |
| 510. |
Write the following steps in sequential order to determine nature of the image formed by a concave mirror when an object is placed between the pole and the prinicpal focus of the mirror, with the help of a ray diagram. (A) Draw two incident light rays, one parallel to the principal axis and the other coming from the center of curvature and draw the paths of the reflected light rays. (B) The reflected light rays are diverging. So, draw the extended lines till they intersect. (C) Draw a concave mirror and mark the pole, the principal focus, the centre of curvature of the mirror. (D) Mark the image at the point of intersection of the extended light rays and write the nature of the image. (E) Draw the principal axis and mark the position of the object on the principal axis between the pole and the principal focus.A. CADBEB. ECBADC. CBAEDD. CEABD |
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Answer» Correct Answer - D Draw a concave mirror and mark the pole, the principal focus and the center of curvature of the mirror. Draw the principal axsi of the mirror and mark the position of the object between the principal focus and pole of the mirror. Draw two incident light rays from the object, one paralled to the principal asis and the other coming from the centre of curvatrue and draw the conrrespoding reflected rays. These reflecting light rays are diverging. So, draw the extended lines till they intersect. Mark the image at a point where the extended light rays intersect and write the nature of the image. |
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| 511. |
An object is placed at 20 cm from the pole of a concave mirror. It forms real image at a distance of 60 cm from the pole. Find the focal length of the concave mirror. |
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Answer» In the given problem, Object distance, u = - 20 cm (using Cartesian sign convention ) image distance , v =- 60 cm (using Cartesian sign convention for real image) Focal length of the mirror is given by, `1/f = 1/u + 1/v` `1 /f=(-1)/20 + (-1)/60` `1/f = (-(60+20))/(60 xx 20) (-80)/(1200)` ` f = (-1200)/80 =- 15` cm The focal length of the given concave mirror is 15 cm. |
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| 512. |
A convex mirror is made by cutting a hollow sphare of radius of curvature 20 cm. Find the focal length of the mirror. |
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Answer» In the given problem, redius of curvature, R = 20 cm. Focal length of the mirror ` = ("Radius of curvature")/2` ` :." focal length , " f= 20/2 = 10` cm. |
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| 513. |
A ray of light passes from one medium to another medium. Refraction takes place when angle of incidence is ……(a) 0° (b) 45° (c) 90° |
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Answer» Correct answer is (b) 45° |
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| 514. |
____________ mirror is used for obtaining real images. |
| Answer» Correct Answer - Concave | |
| 515. |
The focal length of a mirror is +60 cm. Which kind of mirror it is? (a) Concave mirror (b) Parabolic mirror (c) Plain mirror (d) Convex mirror |
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Answer» (d) Convex mirror |
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| 516. |
Which of the following is responsible for the coin appearing shallower when it is kept at the bottom of a water tank? (a) Refraction (b) Reflection (c) Total internal reflection (d) None of these |
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Answer» (a) Refraction |
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| 517. |
Light is falling on surface S1, S2, S3 as shown in Fig.16.1.Surfaces on which the angle of incidence is equal to the angle of reflection is/are(a) S1 only(b) S1 and S2 only(c) S2 and S3(d) all the three surfaces |
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Answer» (d) all the three surfaces |
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| 518. |
Incident angle of a ray of light is 30°. The angle between the incidend ray and the reflected ray is ………. (a)50° (b) 90° (c) 60° (d) 15° |
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Answer» Correct answer is (c) 60° |
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| 519. |
The angle between incident ray and reflected ray is 60°. What is the value of angle of incidence? |
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Answer» The value of angle of incidence 30°. |
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| 520. |
The angle between incident ray and reflected ray is 60°. What is the value of angle of incidence ? |
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Answer» Since angle of incidence = angle of reflection. So, angle of incidence = 30°. |
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| 521. |
The phenomenon of light involved in the fromation of shadow is _______. |
| Answer» Correct Answer - rectilinear propagation | |
| 522. |
An incident ray makes an angle of 75° with the surface of a plane mirror. What will be the angle of reflection? |
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Answer» The angle made by the normal will be 90 – 75 = 15. Angle made by normal is equal to angle of incidence. So i = 15 degree. And by the law of reflection which states that angle of incidence is equal to the angle of reflection, the angle of reflection will be 15 degree. |
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| 523. |
A ray of light strikes a plane mirror XY at an angle of incidence of 65°, is reflected from this plane mirror and then strikes a second plane mirror YZ placed at right angles to the first mirror. What is the angle of reflection for the mirror YZ? |
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Answer» The mirrors XY and YZ are at right angles, i.e., perpendicular. When a ray of light strikes the XY mirror with 65 degree angle, the incident angle will be 90 – 65 = 25 degree on the YZ mirror. Since angle of incidence = angle of reflection, the angle of reflection for YZ mirror will be 25 degrees. |
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| 524. |
An incident ray makes an angle of 65° with the surface of a plane mirror. The angle of reflection in this case will be: A. 65° B. 45° C. 25° D. 35° |
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Answer» D. 35° Angle of incidence is always equal to angle of refection. Hence, angle of reflection will be 35°. |
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| 525. |
Match the entries given in Column A with the appropriate ones in Column B. `{:("Column A","Column B"),(A."A plane mirror",(" ")a."Luminous source"),(B."Virtual image",(" ")b."Can be caught on a screen."),(C."Reflection of light",(" ")c."Magnified"),(D."The Sun",(" ")d."Read"),(E."Real image",(" ")e."Vacuum"),(F."Prism",(" ")f."Image distance is equal to object distance."),(G."Image on the retina",(" ")g."Dispersion"),(H."Velocity of light is maximum",(" ")h."Persicope"):}` |
| Answer» Correct Answer - A : F B : H D : A E : B F : G G : D H : E | |
| 526. |
Match the entries of Column with those of Column B |
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Answer» Correct Answer - `(A) to (b) , (B) to (d) , (C) to (c), (D) to (a)` `(A) to (b), (B) to (d) , (C) to (c), (D) to (a)` |
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| 527. |
Which of the following is (are) true in the case of a plane mirror?A. Objcet distance = image distance.B. Object size = image size.C. The image formed is virtual.D. All the above. |
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Answer» Correct Answer - D The phenomenon which is responsible for vision is irregular reflection. |
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| 528. |
If two plane mirrors are placed with the reflecting surfaces perpendicular to each other, which of the following statement is true?A. The rays incident on the first mirror and the rays reflected from the second mirror are always parallel.B. The rays incident on the first mirror and the rays reflected from the second mirror are perpendicular.C. The angle of deviation lies between `90^(@) and 180^(@)` .D. None of the above. |
| Answer» Correct Answer - A | |
| 529. |
Match the entries given in Column A with the appropriate ones in Column B. `{:("Column A","Column B"),(A."Intensity of light",(" ")a."Plane mirror"),(B."Rainbow",(" ")b."Shadow"),(C."Looking glass",(" ")c."Hot source"),(D."Eclipse",(" ")d."Lumen"),(E."Filament bulb",(" ")e."Dispersion"):}` |
| Answer» Correct Answer - A : D B : E C : A D : B E : C | |
| 530. |
Two plane mirrors are arranged such that their reflecting surfaces are parallel and face each other. When an object is placed between them, the number of images formed are _____.A. 2B. infiniteC. 3D. 4 |
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Answer» Correct Answer - B When two plane mirrors are placed parallel to each other, and when an object is placed between them, then the image of the object formed by any one of the mirror will act like virtual object for other mirror. This proces contnues and infinite numbre of image are formed, (or) `theta=0^(@),n=(360^(@))/(theta)-1=(360^(@))/(0)-1=oo-1=oo` Where n = number of images formed. `theta`= angle between the mirrors. |
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| 531. |
What determines the intensity of light? |
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Answer» The intensity of light is determined by the extent to which the objects emit light. |
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| 532. |
How does eye adjust itself to deal with light of varying intensity? |
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Answer» The iris adjusts the size of pupil according to the light of varying intensity. When the amount of light is very high, the iris contracts the pupil and reduces the amount of light entering the eye. Whereas, when the amount of light is less, the iris expands the pupil so that more light can enter the eye and things can be viewed clearly. |
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| 533. |
Can you now recognize the characteristics of image from rear view mirror? |
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Answer» Erect, virtual and smaller images are formed. |
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| 534. |
What are the characteristics of an image formed by a plane mirror ? |
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Answer» Characteristics of an image formed by a plane mirror : (i) Image formed is virtual and erect in nature. (ii) Object distance always equals to the image distance . (iii) For a real object, the image formed is virtual and vice versa. (iv) Image shows lateral inversion. |
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| 535. |
The intensity of light _______ when the distance from the source increases.A. increasesB. decrasesC. first increases and then decreasesD. remains same |
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Answer» Correct Answer - B The intensity of light decrases, when the distance from the source increases. |
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| 536. |
State the characteristics of the image formed by a plane mirror. |
Answer»
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| 537. |
The image formed by a plane mirror is ______.A. virtualB. realC. invertedD. highly magnified |
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Answer» Correct Answer - A (1) The image formed by a plane mirror is virtural as the image cannot be caught on a screen. (2) It is an erect image. (3) The height of the image is the same as that of the object. |
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| 538. |
Read the following statements and choose the correct option. (A) Moon is a luminous source of light. (B) A glow worm is a natural source of light.A. Only A is trueB. Only B is trueC. Both A and B are trueD. Both A and B are false |
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Answer» Correct Answer - B The moon is not a luminous source of light, it simply reflects the light which is incident on it. A glow worm is a natural source of light. |
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| 539. |
Raed the following statement and choose the correct option. (A) Moon is a luminous source of light. (B) A glow worm is a natural source of light.A. Only A is trueB. Only B is trueC. Both A and B are trueD. Both A and are false |
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Answer» Correct Answer - B The moon is not a luminous source of light, it simply reflects the light which is incident on it. A glow worm is a natural source of light. |
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| 540. |
Why the surface of reflection in a torch light or a headlight of vehicle is made with a concave mirror behind the bulb? |
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Answer» 1. The surface of reflection in a torch light or a headlight of vehicle is made with a concave mirror, behind the bulb. 2. Light released from the bulb falls on the concave surface. 3. After reflection from concave surface, all the light rays travel parallel to each other. 4. So that we can observe focused light at a distance. |
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| 541. |
The diaphragm in a photographic cameraA. controls the exposure time of the film.B. controls the amount of light entering the camera.C. varies the focal length of the lens.D. prevents internal reflection of light. |
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Answer» Correct Answer - B The diaphragm in a photographic camera controls the amount of light entering the camera. |
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| 542. |
Choose the correct statement.A. The final image formed by a terrestrial telescope is inverted.B. The final image formed by an astronomical telescope in erect.C. The final image of an astronomical telescope is magnified.D. Both (a) and (b) |
| Answer» Correct Answer - C | |
| 543. |
Which of the statements is true in case of an astronomical telescope?A. The image of the object is erect when viewed through it.B. The objective is larger in size than the eye piece.C. Eye piece ha sgreater focal length than the objective.D. Eye piece is a convex lens and the objective is a concave lens. |
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Answer» Correct Answer - B For an astronomical telescopes, the objective is larger than the eye piece. |
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| 544. |
Light appears to travel in straight lines sinceA. it passes by the atmosphareB. its wavelength is very smallC. its velocity is very largeD. it is a form of energy |
| Answer» Correct Answer - B | |
| 545. |
Calculate the power of the eye lens of the normal eye, when it is focused at far point and near point, given the diameter of the eye is ` 2.5 ` cm. Find the maximum variation in the power of normal eye lens. |
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Answer» The far point of a normal eye is infinity. When the object is at infinity, the image is formed at the focus, i.e., image distance v = f, where f is the focal length. Diameter of the eye = distance between lens and the focus = ` 2.5` cm(given) ` :. f = 2.5 cm = 2/5 xx 10^(-2)` m . Power of the lens, ` p= 1/f` ` p = 1/(2.5 xx 10^(-2)) = 10^(2)/(2.5) = 40` D. 2. The near point of a normal eye is 25 cm = object distance = - 25 cm = u (form sign convention) ` v = 2.5 ` cm = distance of the eye lens from the retina 9 i.e., the focus) ` 1/f = 1/(2.5 xx 10^(-2)) - 1/(-25 xx 10^(-2))` ` 1/f = 100/2.5 + 100/25` ` 1/f = 40 + 4` ` 1/f = 44` Power = ` 1/f = 44` D. Thus, the maximum variation in the power of the lens is ` 44 D - 40 D = 4 D`. |
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| 546. |
A telescope has an objective of focal length 100 cm and eye piece of focal length 6 cm and the least distance of distinct vision is 25 cm. The telescope is focused for distinct vision of an object at a distance 100 m from the objective. What is the distance of separation between objective and eye piece? |
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Answer» (i) The image formed on the objective is real. Let the image distance be `v_(1)` This image serves as the object for eye piece Determine the object distance for the eye piece `(u_(2))` `:. ` The distance between objective and eye piece = `v_(1) + u_(2)` (ii) `106.89` cm |
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| 547. |
Choose the correct statementA. The combination of a convex lens and a concave lens is a concave lens if the focal length of the convex lens is numerically less than that of concave lens .B. The power of the combination of a concave lens and convex lens is more than the power of individual lenses.C. The combination of a convex lens and concave lens of equal focal length behaves as a glass slab.D. All the above. |
| Answer» Correct Answer - C | |
| 548. |
The focal length of a normal eye lens is aboutA. equal to `2.5`B. `gt 2.5`C. ` lt 2.5`D. Both (a) and (c ). |
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Answer» Correct Answer - D Normal diameter of human eye is ` 2.5` cm. When the eye is focussed on a distant object, the ciliary muscules are relaxed so that the focal length of the eye has its maximum value equal to the diameter of the eye. When the eye is focussed on a closer object, ciliary muscles are strained and the focal length of the eyelens decreases. |
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| 549. |
The power of two lenses are + 6 D and - 4 D , determine the power of the combination of two lenses.A. 6DB. 4DC. 2DD. 3D |
| Answer» Correct Answer - C | |
| 550. |
The angle which the incident ray makes with the mirror is calledA. angle of incidenceB. angle of reflectionC. right angleD. glancing angle of incidence |
| Answer» Correct Answer - D | |