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
Description : In a telescope the object glass of focal length 14 cm, is located at 20 cm from the diaphragm. The focussing lens is midway between them when a staff 16.50 m away is focussed. The focal length of the focussing lens, is (A) 5.24 cm (B) 6.24 cm (C) 7.24 cm (D) 8.24 cm
Last Answer : (C) 7.24 cm
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 : Magnifying Glass is basically a (1) Plano-concave lens (2) Concave lens (3) Convex lens (4) Cylindrical lens
Last Answer : Convex lens
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 : 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 : 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 : 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 : When beam of parallel rays of light falls on _______ then all the rays of light converge . a) convex lens b)concave lens c)plain mirror d)plano concave lens
Last Answer : a) convex lens
Description : Persons suffering from myopia are advised to use (1) convex lens (2) concave lens (3) plano-convex lens (4) plano-concave lens
Last Answer : concave lens
Description : Cross hairs in surveying telescopes, are fitted (A) In the objective glass (B) At the centre of the telescope (C) At the optical centre of the eye piece (D) In front of the eye piece
Last Answer : (D) In front of the eye piece
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 : The focal length of a plano-convex lens is 20 cm in air. Refractive index of glass is 1.5. Calculate (i) the radius of curvature of lens surface and (
Last Answer : The focal length of a plano-convex lens is 20 cm in air. Refractive index of glass is 1.5. ... length when immersed in liquid of refractive index 1.6
Description : Newton's rings are formed because of interference between the light Reflected from (a) Upper surface of Plano-convex lens and lower surface of plane glass plate (b) Lower surface of Plano-convex ... c) Lower and upper surface of Plano-convex (d) Lower and upper surfaces of plane glass plate
Last Answer : (b) Lower surface of Plano-convex lens and upper surface of plane glass plate
Description : Flint glass (A) Has slightly the greater refracting power than crown glass (B) Has roughly double refracting power than that of crown (C) And crown glass proportions yield the required focal length ... dispersion produced by the convex lens at the emergence from the concave (D) All the above
Description : While viewing through a level telescope and moving the eye slightly, a relative movement occurs between the image of the levelling staff and the cross hairs. The instrument is (A) Correctly focussed (B) Not correctly focussed (C) Said to have parallax (D) Free from parallax
Last Answer : (C) Said to have parallax
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 : 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 type of mirror used in automobiles to see the traffic on the rear side is (1) Concave (2) Plano-Convex (3) Plane (4) Convex
Last Answer : Convex
Description : In an internal focusing telescope (A) The objective is at a fixed distance from the diaphragm (B) The focusing is done by the sliding of a divergent lens (C) The focusing divergent lens is situated at about the middle of the tube (D) All the above
Description : A concave lens is placed in the path of convergent rays. The rays are focussed on the axis 15 cm behind the lens. Where would these rays have been foc
Last Answer : A concave lens is placed in the path of convergent rays. The rays are focussed on the axis 15 cm behind ... lens ? Focal length of the lens is 30 cm.
Description : Diaphragm of a surveying telescope is held inside (A) Eye-piece (B) Objective (C) Telescope tube at its mid point (D) Telescope at the end nearer the eye-piece
Last Answer : (D) Telescope at the end nearer the eye-piece
Description : Pick up the correct statement from the following: (A) The diaphragm is placed between eyepiece and the objective but nearer to the former (B) The diaphragm is placed between the eyepiece and objective ... outer component of the objective is a double-convex lens of crown glass (D) All the above
Description : The head mirror used by ENT doctors is (1) Concave (2) Convex (3) Plane (4) Plano-convex
Last Answer : Concave
Description : Which of the following can be used as a burning glass? (a) Plane mirror (b) Convex mirror (c) Concave lens (d) Concave mirror
Last Answer : Ans:(d)
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.
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 : Prism
Description : Removal of parallax, may be achieved by focussing (A) The objective (B) The eye-piece (C) The objective and the eye-piece (D) None of these
Last Answer : (C) The objective and the eye-piece
Description : A plano-convex lens `(mu = 1.5)` has a curved surface of radiys 15 cm. what is its focal length ?
Last Answer : A plano-convex lens `(mu = 1.5)` has a curved surface of radiys 15 cm. what is its focal length ?
Description : Why in Newton's rings setup, the beam splitter (mirror) is kept at 450? (a) It allows light rays to incident at 450over the top surface of Plano convex lens (b) It allows light rays to ... Plano convex lens (d) It allows light rays to incident at 900over the top surface of Plano convex lens
Last Answer : (d) It allows light rays to incident at 900over the top surface of Plano convex lens
Description : In Newton’s rings experiment, if we reduce the radius of curvature of Plano Convex lens to zero, what will be effect on Newton’s rings? (a)They will become more bright (b)They will become more dark ( c)They will disappear (d) They will be more dense
Last Answer : ( c)They will disappear
Description : Newton's rings experiment is performed and radius (or diameter) is calculated. Now Plano-convex lens is replaced with another Plano-convex lens of greater Radius of curvature. What will be effect on radius ( ... ) will increase (c) Radius (or diameter) will decrease (d) There will be no effect
Last Answer : (b) Radius (or diameter) will increase
Description : In Newton’s rings experiment, if we reduce the radius of curvature of Plano convex lens to zero, what will be effect on Newton’s rings? A. They will become brighter B. They will become darker C. They will disappear D. They will be more dense
Last Answer : C. They will disappear
Description : In Newton's ring experiment, the diameter of the 15 th ring was found to be 0.590 and that of the 5 th ring was 0.336 cm. If the radius of Plano convex lens is 100 cm, compute the wavelength of light used. A. 5885 A 0 B. 5880 A o C. 5890 A o D.5850 A
Last Answer : B. 5880 A o
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 : The power of a lens (A) Is reciprocal of its focal length (B) Is positive if it is a convex lens (C) Is negative if it is a concave lens (D) Is measured in Diopter
Last Answer : (D) Is measured in Diopter
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 : 1. A convex lens of glass has power P in air. If it is immersed in water, what will be its power? 2. The internal secretion of which acid helps in digestion? 3. Who is responsible for ... 19. 17th Parallel separates which country? 20. Who established Fergusson College at Pune in the year 1885 ?
Last Answer : Answer : 1. Less than P 2. Hydrochloric acid 3. Election Commission 4. Asia 5. Gopala 6. Direct tax 7. Shooting 8. Acetylene 9. Titusfills in Pennsylvania, U.S.A. 10. Makrana marble 11 ... Demand draft 17. Infra-red-waves 18. Permanent tissue 19. North and South Vietnam 20. Deccan Education Society
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.
Last Answer : Concave lens
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 : 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 ?
Description : The focal length of a concave-convex lens of radii of curvature 5 cm and 10 cm is 20 cm. what will be its focal length in water ? Given `.^(a)mu_(w) =
Last Answer : The focal length of a concave-convex lens of radii of curvature 5 cm and 10 cm is 20 cm. what will be its ... water ? Given `.^(a)mu_(w) = 4//3`.
Description : Which one of the following can be used to focus sunlight? A. Plane mirror B. Concave lens C. Concave mirror D. Convex mirror
Last Answer : ANSWER: C
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 : 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: In Astigmatism, eye cannot see objects in two orthogonal directions clearly simultaneously. This abnormality is removed by using cylindrical 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).