Who modernizes convex lenses ?

1 Answer

Answer :

Al Hazen by modernizing convex lenses.

Related questions

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 : 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 : 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 : A microscope that has two sets of lenses : an occular lens and an eyepiece.

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 : 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 : 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 : 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 

Last Answer : (D) All the above 

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 : 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

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 : How many types of lenses and what are they ?

Last Answer : Two types. 1. Convex 2. Concave

Description : An electron microscope gives higher magnification than an optical microscope, because: (1) It uses more powerful lenses (2) the velocity of electron is smaller than that of visible (3) the ... particles (4) the wavelength of electrons is smaller as compared to the wavelength of visible light

Last Answer : (4) the wavelength of electrons is smaller as compared to the wavelength of visible light Explanation: An electron microscope uses a beam of electrons to illuminate a specimen and produce a ... photons. Magnification is the process of enlarging something only in appearance, not in physical size.

Description : An electron microscope gives higher magnifications than an optical microscope because - (1) The velocity of electrons is smaller than that of light (2) The wavelength of electrons is smaller as ... have more energy than the light particulars (4) The electron microscope uses more powerful lenses

Last Answer : (2) The wavelength of electrons is smaller as compared to the wavelength of visible light Explanation: An electron microscope is a microscope that uses a beam of accelerated electrons as a spume ... a higher resolving power than a light microscope and can reveal the structure of smaller objects.

Description : Rainbow is seen after rain because of hanging molecules of water which act as – (1) lenses (2) mirrors (2) prisms (4) slabs

Last Answer : (2) mirrors Explanation: In optics, a prism is a transparent optical element with flat, polished surfaces that refract light. In a rainbow, raindrops in the air act as tiny prisms. Light enters the raindrop ... In the process, it is broken into a spectrum just like it is in a triangular glass prism.

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 who is nearsighted will need what type of lenses in his glasses in order to see correctly?

Last Answer : ANSWER: DIVERGING or CONCAVE LENSES

Description : An electron microscope gives higher magnifications than an optical microscope because : (1) The velocity of electrons is smaller than that of light (2) The wavelength of electrons is smaller as ... have more energy than the light particulars (4) The electron microscope uses more powerful lenses 

Last Answer : The wavelength of electrons is smaller as compared to the wavelength of visible light

Description : Rainbow is seen after rain because of hanging molecules of water which act as (1) lenses (2) mirrors (2) prisms (4) slabs

Last Answer : mirrors

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 : An electron microscope gives higher magnification than an optical microscope, because : (1) it uses more powerful lenses (2) the velocity of electron is smaller than that of visible light (3) ... particles (4) the wavelength of electrons is smaller as compared to the wavelength of visible light

Last Answer : the wavelength of electrons is smaller as compared to the wavelength of visible light

Description : A convex lens has a focal length of 10 cm. At what distance from the lens should the object be placed so that it forms a real and inverted image 20 cm away from the lens? What would be the size of ... ? With the help of a ray diagram show the formation of the image by the lens in this case. -Physics

Last Answer : This is the Answe:

Description : An object 2 cm high is placed at a distance of 64 cm from a white screen. On placing a convex lens at a distance of 32 cm from the object it is found that a distinct image of the object ... diagram to show the formation of the image in this position of the object with respect to the lens. -Physics

Last Answer : Since, object-screen distance is double of object-lens separation, the object is at a distance of 2f from the lens and the image should be of the same size of the object.

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 : An object 50 cm tall is placed on the principal axis of a convex lens. Its 20 cm tall image is formed on the screen placed at a distance of 10 cm from the lens. Calculate the focal length of the lens. -Physics

Last Answer : The focal length' of convex length is 7.14 cm. Solution: The given quantities are Height of the object h = 50 cm Height of the image formed h' = -20 cm Image distance v = 10 cm The image ... object distance will be So the focal length will be Thus the focal length of the convex lens is 7.14 cm

Description : What is a convex lens ?

Last Answer : A convex lens is a lens that has a thick center and a narrow end.

Description : What is a convex mirror ?

Last Answer : If the regular reflection of light occurs from the convex surface of a spherical mirror, then that mirror is called convex mirror.

Description : What is the shape of convex lens ?

Last Answer : The center of a convex lens is thicker and the edges are narrower

Description : What is the power of a convex lens with a focal length of 20 cm ?

Last Answer : 20cm = 0.2 m We know , power p = 1 / f = 1 / 0.2 = + 5 D

Description : What kind of reflection does a convex lens produce ?

Last Answer : Convex or convergent lenses form real and inverted reflections.

Description : A convex mirror makes a good rear-view mirror for a car. Why?

Last Answer : – It forms erect, reduced images

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 : Convex mirrors are used as a rear view mirror in motor cycles because (1) it forms real image (2) it forms erect (upright) image (3) it forms smaller image as compared with object (4) All of the above

Last Answer : (3) it forms smaller image as compared with object Explanation: It is because image formed by an convex mirror is always virtual, erect and smaller than the object.

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 : 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 : Convex mirror is generally used in - (1) solar cookers (2) opthalmoscope (3) reflector for head light (4) rear view mirror

Last Answer : (4) rear view mirror Explanation: Rear view mirrors of carsare convex mirrors as they enable the driver to see a wide area of the road behind the car. The convex mirror makes the rays of ... if they were coming from its focus, thereby produdcing a diminished virtual image which the driver can see.

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 : 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 : An object is placed on the principal axis of a convex lens of focal length 10 cm. If the distance of the object from the lens is 30 cm, what is the distance of the image formed? (1) 20 cm (2) 15 cm (3) 30 cm (4) 10 cm

Last Answer : (2) 15 cm

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 : 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 : 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 : `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 : 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.