Description : Based on the diagram shown, what kind of lens is used to make the overhead projector? (a) concave lenses (b) convex lenses (c) bifocal lenses (d) flat lenses
Last Answer : (b) convex lenses
Description : Which one of the following lenses should be used to correct the defect of astigmatism? (1) Cylindrical lens (2) Concave lens (3) Convex lens (4) Bifocal lens
Last Answer : (1) Cylindrical lens Explanation: Astigmatism is an optical defect in which vision is blurred due to the inability of the optics of the eye to focus a point object into a sharp focused image ... lens, and cannot be corrected by standard spectacle lenses, but can be corrected by contact lenses.
Description : Hyperrnetropia or longsight can be corrected by using : (1) Bifocal lenses (2) Cylindrical lenses (3) Concave lenses (4) Convex lenses
Last Answer : (4) Convex lenses Explanation: It can be corrected with convex lenses in eyeglasses or contact lenses. Convex lenses have a positive dioptric value, which causes the light to focus closer than its normal range.
Description : Hypermetropia or longsight can be corrected by using : (1) Bifocal lenses (2) Cylindrical lenses (3) Concave lenses (4) Convex lenses
Last Answer : Convex lenses
Description : Which one of the following lenses should be used to correct the defect of astigmatism ? (1) Cylindrical lens (2) Concave lens (3) Convex lens (4) Bifocal lens
Last Answer : Cylindrical lens
Description : Pick up the correct statement from the following: (A) Spherical aberration may be reduced by diminishing the aperture (B) Spherical aberration may be minimised by replacing the single lens by a ... telescope objectives, a combination of convex lens and concave lens is used (D) All the above
Last Answer : (D) All the above
Description : Which among the following lens is used to correct Presbyopia? (1) Concave (2) Convex (3) Cylindrical (4) Bifocal
Last Answer : (4) Bifocal Explanation: Presbyopia is a condition associated with aging of the eye those results in progressively worsening ability to focus clearly on close objects. By far the most common treatment 4 for presbyopia is bifocal or pro gressive lens eyeglasses.
Description : `Short-sight' in human eye can be corrected by using proper – (1) convex lens (2) concave lens (3) cylindrical lens (4) bifocal lens
Last Answer : (2) concave lens Explanation: Scintillation or twinkling is generic terms for variations in apparent brightness or position of a distant luminous object viewed through a medium. If ... is termed astronomical scintillation; within the atmosphere, the phenomenon is termed terrestrial scintillation.
Description : Spectacles used for viewing 3D films have – (1) Bifocal lens (2) Convex lens (3) Concave lens (4) Polaroid
Last Answer : (4) Polaroid Explanation: A polarized 3D system uses polarization glasses to create the illusion of three-dimensional images by restricting the light that reaches each eye, an example of stereoscopy. ... and blocks the light polarized in the opposite direction, each eye sees a different image.
Description : Spectacles used for viewing 3D films have (1) Bifocal lens (2) Convex lens (3) Concave lens (4) Polaroids
Last Answer : Polaroids
Description : ‘Short-sight’ in human eye can be corrected by using proper (1) convex lens (2) concave lens (3) cylindrical lens (4) bifocal lens
Last Answer : concave lens
Description : Sumati did some preliminary experiment with the lenses and found out that the magnification of the eyepiece (L 2 ) is 3. If in her experiment with L 2 she found an image at 24 cm from the lens, at what distance did she put the object? (a) 72 cm (b) 12 cm (c) 8 cm (d) 6 cm
Last Answer : (c) 8 cm
Description : Pick up the correct statement from the following: (A) A refracting telescope consists optically of two lenses (B) The principal axes of both the lenses coincide the optical axis of the telescope (C) The lens nearer the object to be viewed is convex and is called objective (D) All the above
Description : An internal focussing type surveying telescope, may be focussed by the movement of (A) Objective glass of the telescope (B) Convex-lens in the telescope (C) Concave lens in the telescope (D) Plano-convex lens in the telescope
Last Answer : (C) Concave lens in the telescope
Description : Which lenses are used by people having short-sightedness? A. Convex B. Concave (Answer) C. Concavo-convex D. Plain
Last Answer : B. Concave (Answer)
Description : What is a compound microscope? (1) A microscope that has one lens. (2) A microscope that has two sets of lenses : an occular lens and an eyepiece. (3) A microscope whose lenses are concave. (4) A microscope whose lenses are convex.
Last Answer : (2) A microscope that has two sets of lenses : an occular lens and an eyepiece. Explanation: A compound microscope is a microscope which uses multiple lenses to collect light from the ... lens provides the primary magnification which is compounded (multiplied) by the ocular lens (eyepiece).
Description : Two concave lenses of 60 cm focal length are cemented on either side of a convex lens of 15 cm focal length. The focal length of the combination is (A) 10 cm (B) 20 cm (C) 30 cm (D) 40 cm
Last Answer : (C) 30 cm
Description : What is lens? Explain the difference between convex and concave lenses.
Last Answer : Lens: A lens is a piece of glass or other transparent material like plastic whose one or both side is spherical. Types There are two types of lenses. 1. Convex lens 2. Concave lens Convex lens ... thinner at the edges. Concave lens Concave lens is thinner in the middle and thicker at the edges.
Description : Ramsden eye-piece consists of (A) Two convex lenses short distance apart (B) Two concave lenses short distance apart (C) One convex lens and one concave lens short distance apart (D) Two Plano-convex lenses short distance apart, with the convex surfaces facing each other
Last Answer : (D) Two Plano-convex lenses short distance apart, with the convex surfaces facing each other
Last Answer : A microscope that has two sets of lenses : an occular lens and an eyepiece.
Description : Draw the ray diagram in each case to show the position and nature of the image formed when the object is placed: (i) at the centre of curvature of a concave mirror (ii) between the pole P and focus F of ... front of a convex mirror (iv) at 2F of a convex lens (v) in front of a concave lens -Physics
Last Answer : Answer. Nature of image: Real, inverted and same size image is formed at the centre of curvature. Nature of image: Virtual, enlarged and erect image is formed behind the mirror. Nature of image: Virtual ... : Virtual, erect and diminished image is formed between O and F on the same side of object.
Description : In an UDL fixed beam free moment diagram gives a bending moment of a. Convex up b. Convex down c. Concave up d.Concave down
Last Answer : b. Convex down
Description : In the following diagram are shown the position of an object O, image I and two lenses. The focal length of one lens is also given. Determine the foca
Last Answer : In the following diagram are shown the position of an object O, image I and two lenses. The ... given. Determine the focal length of the other lens.
Description : A person wears spectators with concave lenses. It means that normally (when not using glasses), the image of distant objects is focused in his eyes – (1) behind the retina (2) in front of the retina (3) on the retina (4) on the blind spot
Last Answer : (2) in front of the retina Explanation: A concave lens is used to correct short-sightedness (myopia). In myopia, images are formed in front of the retina, resulting in a blurred image. This ... relatively too long or the refractive powers of the cornea and lens of the eye are relatively too strong.
Description : A person wears spectates with concave lenses. It means that normally (when not using glasses), the image of distant objects is focussed in his eyes (1) behind the retina (2) in front of the retina (3) on the retina (4) on the blind spot
Last Answer : in front of the retina
Description : Who modernizes convex lenses ?
Last Answer : Al Hazen by modernizing convex lenses.
Description : Pick up the correct specification of Ramsden eyepiece from the following: (A) It consists of two equal piano convex lenses (B) The curved surfaces of Plano-convex lenses face each other (C) ... from a point on the diaphragm enter the eye as a parallel beam (D) All the above
Description : What type of mirror is used by motorists to see the road behind them? (a) Convex (b) Concave (c) Plane (d) Concave-convex
Last Answer : Ans:(a)
Description : When light enters a closed room through a small hole in the door, the image of an outside building appears as inverted on the opposite wall. This is because (a) The hole acts as a convex lens (b) ... the edges of the hole (c) Of rectilinear propagation of light (d) The hole acts as a concave lens
Last Answer : Ans:(b)
Description : The type of mirror used in the headlamps of cars is the (a) plane mirror (b) spherical convex mirror (c) spherical concave mirror (d) parabolic concave mirror
Last Answer : Ans:(d)
Description : For the rear view, motorists use (a) plane mirror (b) concave mirror (c) convex mirror (d) cylindrical mirror
Last Answer : Ans:(c)
Description : Which of the following can be used as a burning glass? (a) Plane mirror (b) Convex mirror (c) Concave lens (d) Concave mirror
Description : What type of mirror can be used to obtain the real image of an object? (a) Plane mirror (b) Concave mirror (c) Convex mirror (d) No mirror can produce a real image
Description : The lens used in a simple microscope is------? A. Concave B. Convex (Answer) C. Cylindrical D. None
Last Answer : B. Convex (Answer)
Description : The Mirror used in the Automobiles are------? A. Concave B. Convex (Answer) C. Plains D. Reflective
Description : Short-sight defect could be corrected by a ------- lens? A. concave lens (Answer) B. convex lens C. converging lens D. none of these
Last Answer : A. concave lens (Answer)
Description : The rear view mirror of a motor vehicle is ----? A. Concave B. Plane C. Convex (Answer) D. Biconcave
Last Answer : C. Convex (Answer)
Description : Short-sightedness can be corrected by using ------? A. Convex lens B. Concave lens (Answer) C. Convex-concave lens D. Concave-convex lens
Last Answer : B. Concave lens (Answer)
Description : Myopia is a defect of Human eye. it can be corrected by using a lens called? A. Convex lens B. Concave lens (Answer) C. Cylindrical lens D. Plano convex lens E. None of these
Description : A camera uses a ----- to form an image. A. convex lens (Answer) B. concave lens C. condenser lens D. none of these
Last Answer : A. convex lens (Answer)
Description : Long-sight defect could be corrected by using ----- lens? A. concave B. Convex (Answer) C. diverging D. none of these
Description : Why is concave mirror used and not convex mirror? (a) because concave mirror can give real image. (b) because convex mirror can give real image. (c) because concave mirror cannot give real image. (d) because convex mirror cannot give virtual image.
Last Answer : (a) because concave mirror can give real image.
Description : A boy is standing in front of and close to a special mirror. He finds the image of his head bigger than normal, the middle part of his body of the same size, and his legs smaller than normal. The ... , Plane, Concave (b) Plane, Convex, Concave (c) Concave, Plane, Convex (d) Convex, Concave, Plan
Last Answer : (c) Concave, Plane, Convex
Description : A real image of an object is to be obtained. The mirror required for this purpose is : (a) convex mirror (b) concave mirror (c) plane mirror (d) either convex or concave mirror
Last Answer : (c) plane mirror
Description : What is Concave Slope and Convex Slope? Explain? -SST 10th
Last Answer : Concave Slope: The slope is very gentle at the foot and it goes on getting steeper and steeper towards the top. The spacing between successive contours at the lower level is more than at the ... diagram. The spacing between successive contours at the lower level is less than at the higher level.
Description : report about convex and concave
Last Answer : Make a list of all the convex and concave reflecting surface in your home and surroundings. Prepare ... your findings please i want it by report
Description : Ray coming from an object situated at infinity, fall on a convex lens and an image is formed at a distance of 16 cm from the lens. When a concave lens
Last Answer : Ray coming from an object situated at infinity, fall on a convex lens and an image is formed ... . Calculate the focal length of the concave lens.
Description : A concave lens is kept in contact with a convex lens of focal length `20 cm`. The combination works as a converging lens of focal length `100 cm`. Cal
Last Answer : A concave lens is kept in contact with a convex lens of focal length `20 cm`. The combination ... length `100 cm`. Calculate power of concave lens.
Description : Find the focal length and power of a convex lens, which when placed in contact with a concave lens of focal length `25 cm` forms a real image `5` time
Last Answer : Find the focal length and power of a convex lens, which when placed in contact with a concave ... the object placed `20 cm` from the combination.
Description : A compound lens has been formed by joinined a convex and a concave lens, each of focal length 30 cm. what is the focal length of the combination? What
Last Answer : A compound lens has been formed by joinined a convex and a concave lens, each of focal length 30 ... of the combination? What will be the power ?