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 : `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 : ‘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 : 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 : 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 : 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 : 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 : Based on the diagram shown, what kind of lenses would Sumati need to make the telescope? (a) Concave lenses (b) Convex lenses (c) Bifocal lenses
Last Answer : (b) Convex lenses
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
Last Answer : B. Concave lens (Answer)
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-sightedness can be corrected by using ------? A. Convex lens B. Concave lens (Answer) C. Convex-concave lens D. Concave-convex lens
Description : Long-sight defect could be corrected by using ----- lens? A. concave B. Convex (Answer) C. diverging D. none of these
Last Answer : B. Convex (Answer)
Description : Short-sightedness can be corrected by using A.Convex lens B.Concave lens C.Convex-concave lens D.Concave-convex lens
Last Answer : B.Concave lens
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).
Last Answer : A microscope that has two sets of lenses : an occular lens and an eyepiece.
Description : What type of lens is used to correct vision of a person suffering from Myopia? (1) Convex lens (2) Concave lens (3) Crossed lens (4) Cylindrical lens
Last Answer : (2) Concave lens Explanation: Near-sightedness, also known as short-sightedness and myopia, is a condition of the eye where light focuses in front of, instead of on, the retina. This causes distant objects to be blurry while close objects appear normal.
Description : Magnifying Glass is basically a – (1) Plano-concave lens (2) Concave lens (3) Convex lens (4) Cylindrical lens
Last Answer : (3) Convex lens Explanation: A magnifying glass is a convex lens that is used to produce a magnified image of an object. The magnification of a magnifying glass depends upon where it is placed between the user's eye and the object being viewed, and the total distance between them.
Description : Which one of the following is used to remove Astigmatism for a human eye? (1) Concave lens (2) Convex lens (3) Cylindrical lens (4) Prismatic lens
Last Answer : (3) Cylindrical lens Explanation: A cylindrical lens is a lens which focuses light into a line instead of a point, as a spherical lens would.
Description : The type of mirrors used in the headlamp of cars is – (1) Parabolic concave (2) Plane (3) Spherical convex (4) Cylindrical concave
Last Answer : (1) Parabolic concave Explanation: Curved mirror that reflects light from its inner surface, the curve being inward. It may be either circular or parabolic in section. A concave mirror converges parallel light ... is not too close to the mirror. A real image is formed at the point of convergence.
Description : You want to put up a mirror at a blind corner in a building. Which of the following will give you the largest field of view? Is it a: w) convex mirror x) concave mirror y) cylindrical mirror z) plane mirror
Last Answer : ANSWER: W -- CONVEX MIRROR
Last Answer : Concave lens
Description : Magnifying Glass is basically a (1) Plano-concave lens (2) Concave lens (3) Convex lens (4) Cylindrical lens
Last Answer : Convex lens
Description : The type of mirrors used in the headlamp of cars is (1) parabolic concave (2) plane (3) spherical convex (4) cylindrical concave
Last Answer : parabolic concave
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 : 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 : 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 : 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 : 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
Description : For the rear view, motorists use (a) plane mirror (b) concave mirror (c) convex mirror (d) cylindrical mirror
Last Answer : Ans:(c)
Last Answer : (3) Cylindrical lens Explanation: In Astigmatism, eye cannot see objects in two orthogonal directions clearly simultaneously. This abnormality is removed by using cylindrical lens.
Description : The lens used in a simple microscope is------? A. Concave B. Convex (Answer) C. Cylindrical D. None
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 : The mirror used for the head light of a car is – (1) spherical concave (2) plane (3) cylindrical (4) parabolic concave
Last Answer : (4) parabolic concave Explanation: A parabolic (or paraboloid or paraboloidal) reflector(or dish or mirror) is a reflective surface used to collect or project energy such as light, sound, or radio waves.
Description : Can astigmatism be corrected by lenses during cataract surgery?
Last Answer : What's possible in today's world of eyecare is simply amazing. There are now specialty lenses that treat astigmatism that are used after cataract surgery, effectively improving the patient's vision.
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 : If you look into a mirror and find that the image (your reflexion) is smaller than you, then the type of the mirror is - (1) plano-concave mirror (2) concave mirror (3) plane mirror (4) convex mirror
Last Answer : (4) convex mirror Explanation: A convex mirror, diverging mirror, or fish eye mirror is a curved mirror in which the reflective surface bulges toward the light source. Such mirrors always form a virtual image and the image is smaller than the object.
Description : The type of minor used in automobiles to see the traffic on the rear side is – (1) Concave (2) Plano-Convex (3) Plane (4) Convex
Last Answer : (4) Convex Explanation: Convex mirrors are used as rear view mirrors in automobiles to see the traffic on the rear side. A convex mirror always produces an erect image of the objects. The image formed in ... the object, due to which a convex mirror gives a wide field of view of the traffic behind.
Description : The mirror used by ENT specialist is: (1) Plane mirror (2) Concave mirror (3) Convex mirror (4) None of these
Last Answer : (2) Concave mirror Explanation: To see the inner part of ear and other parts, E.N.T doctors use a concave mirror. When the rays of light falls on reflecting surface of concave mirror, that time Concave mirror concentrate those all the rays at its focus.
Description : Vehicles use ______ to see the objects coming from behind. (1) Concave lens (2) Convex lens (3) Convex mirror (4) Concave mirror
Last Answer : (2) Convex lens Explanation: Convex mirror is used in rear view mirror of vehicles; so that the driver can see the traffic coming from behind. The field of view is widest in case of a convex mirror, which enables it to show a wider area from behind.
Description : Persons suffering from myopia are advised to use – (1) convex lens (2) concave lens (3) piano-convex lens (4) plano-concave lens
Last Answer : (2) concave lens 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 occurs when the ... too long or the refractive powers of the cornea and lens of the eye are relatively too strong.
Description : Shaving mirror is – (1) Convex (2) Concave (3) Plane (4) Parabolic
Last Answer : (2) Concave Explanation: Concave mirrors are used in makeup or shaving mirrors. When shaving or applying makeup, a person holds the mirror close to her face. This allows him to see an enlarged image of him face, which is helpful for applying makeup or shaving correctly.
Description : Which type of mirror is used in the head lights of vehicles? (1) Plane mirror (2) Concave mirror (3) Convex mirror (4) Parabolic mirror
Last Answer : (2) Concave mirror Explanation: Car head lights have concave mirrors because it collects and focuses as much as possible of the light from the bulb and send it out as a fairly tight beam in one ... at the focal point. The reflected light is parallel and gives more visibility to the driver at night.
Description : A camera uses a ______ to form an image on a piece of film at the back. (1) convex lens (2) concave lens (3) diverging lens (4) none of these
Last Answer : (1) convex lens Explanation: A camera consists of three main parts. • The body which is light tight and contains all the mechanical parts. • The lens which is a convex lens. • The film or a charged couple device in the case of a digital camera.
Description : A rear-view mirror for driving is – (1) plain (2) concave (3) convex (4) inverted
Last Answer : (3) convex Explanation: The kind of mirror used in the rear-view mirror must be convex mirrors, because it creates smaller, yet still upright images. Concave mirrors would create an inverted image and ... make everything smaller so this allows the driver to see a greater range of things behind him.
Description : A simple microscope consists of : (1) a short focus convex lens (2) a long focus convex lens (3) a short focus concave lens (4) a long focus concave lens
Last Answer : (1) a short focus convex lens Explanation: Simple microscope - light microscope consisting of a short focus single convex lens is used to produce an enlarged image. The magnifying glass was ... object viewed and one lens, increasing the visibility of the object by some amount (magnification).
Description : Which of the following is used to split white light into different colours? (1) Glass slab (2) Convex lens (3) Concave lens (4) Prism
Last Answer : (4) Prism Explanation: In optics, a prism is a transparent optical element with flat, polished surfaces that refract light. At least two of the flat surfaces must have an angle between them. The ... a triangular base and rectangular sides, and in colloquial use "prism" usually refers to this type.