Description : The magnifying power of an astronomical telescope can be decreased by – (1) decreasing the focal length of the eyepiece (2) increasing the focal length of the eyepiece (3) increasing the focal length of the objective (4) None of these
Last Answer : (2) increasing the focal length of the eyepiece Explanation: The magnifying power (M) of astronomical is given by M = (focal length of objective)/(focal length of eye piece). This ... piece should be small. Similarly, for decreased magnification, focal length of eye piece should be increased.
Description : The magnifying power of an astronomical telescope can be decreased by (1) decreasing the focal length of the eyepiece (2) increasing the focal length of the eyepiece (3) increasing the focal length of the objective (4) None of these
Last Answer : increasing the focal length of the eyepiece
Description : Magnifying power of a simple microscope can be increased by ? A. increasing focal length of the lens B. Decreasing focal length of the lens (Answer) C. Lens of large aperture D. lens of short aperture E. None of these
Last Answer : B. Decreasing focal length of the lens (Answer)
Description : Magnification of compound microscope is not connected with (a) numerical aperture (b) focal length of objective (c) focal length of eye piece (d) tube length.
Last Answer : (a) numerical aperture
Description : Pick up the correct statement from the following: (A) In astronomical telescope, the rays from the object after refraction at the objective are brought to a focus before entering the eyepiece to produce ... the objective traversing through the eyepiece, is called line of sight (D) All the above
Last Answer : (D) All the above
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 : Which one of the following determines the sharpness of image in a camera? (1) The aperture (2) The exposure time (3) The focal length of the lens (4) Size of the camera
Last Answer : (1) The aperture Explanation: Image quality is a characteristic of an image that measures the perceived image degradation (typically, compared to an ideal or perfect image). Imaging systems may ... assessment is an important problem. Sharpness determines the amount of detail an image can convey.
Description : Your Minolta camera has a 50 millimeter lens. The 50 millimeters is the lens' w) diameter x) focal length y) magnification z) aperture
Last Answer : ANSWER: X -- FOCAL LENGTH
Description : Which one of the following determines the sharpness of image in a camera ? (1) The aperture (2) The exposure time (3) The focal length of the lens (4) Size of the camera
Last Answer : The aperture
Description : What is the power of the objective lens of a microscope if an eyepiece of power 10x is used and the total magnification of the object is 40x? (A) 4 (B) 10 (C) 40 (D) 400
Last Answer : (A) 4
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 : Resolving power of a telescope depends on (A) The diameter of the aperture (B) The pupil aperture of the eye (C) The diameter of the object glass (D) All the above
Description : If a light microscope has an eyepiece lens of magnification x15 what magnification of objective lens would be needed to get a total magnification of x1500?
Last Answer : The total magnification is equal to the magnification of theeyepiece multiplied by the magnification of the objective lens.So in this case the objective lens would need to be 100X.
Description : How do you find the total magnification of the eyepiece and the objective lens?
Last Answer : Need answer
Description : A student wishes to study the cell structure under a light microscope having 10X eyepiece and 45X objective. He should illuminate the object by which one of the following colours of light so as to get the best possible resolution? (a) Blue (b) Green (c) Yellow (d) Red
Last Answer : (a) Blue
Description : Pick up the correct statement from the following: (A) The eyepiece plays no part in defining the line of sight (B) The diaphragm plays no part in defining the line of sight (C) The optical centre of the objective plays no part in defining the line of sight (D) None of these
Last Answer : (A) The eyepiece plays no part in defining the line of sight
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 : Which one of the following statements is not correc t? (a) Parallax error is eliminated when there is no change in the staff reading when eye is moved up and down (b) The objective lens is ... (d) The eyepiece need not be adjusted after the first set up when the same surveyor is taking readings
Last Answer : (b) The objective lens is to be focused towards a white or bright background for clear visibility of cross-hairs
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
Description : If is the stadia distance, is the focal length and is the distance between the objective and vertical axis of the techeometer, the multiplying constant, is (A) f/i (B) i/f (C) (f + d) (D) f/d
Last Answer : (A) f/i
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 : 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 : 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 : 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 : 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 imaginary line passing through the intersection of cross hairs and the optical centre of the objective, is known as (A) Line of sight (B) Line of collimation (C) Axis of the telescope (D) None of these
Last Answer : (B) Line of collimation
Description : The real image of an object formed by the objective must lie (A) In the plane of cross hairs (B) At the centre of the telescope (C) At the optical centre of the eye-piece (D) Anywhere inside the telescope
Last Answer : (A) In the plane of cross hairs
Description : Why don't they construct giant magnifying lenses to create heat and power?
Last Answer : We already do This is probably what you pictured in your head, but it is exactly the same thing on a very large scale. excerpt Creating and storing power was the easy part. Far trickier was finding a way to deal with the stresses created by “radiation fluxes”
Description : What are The greatest difference in magnifying power is between?
Description : The ratio of the distances at which a stated length can be distinguished by the telescope and the human eye, respectively, is called (A) Brightness of telescope (B) Magnification of telescope (C) Resolving power of telescope (D) None of these
Last Answer : (C) Resolving power of telescope
Description : For C band Synthetic Aperture Radar (SAR) with Doppler band width of 1300 Hz, the coherence length loch is: (A) 130 km (B) 230 km (C) 250 km (D) 500 km
Last Answer : Answer: Option B
Description : The power of a convex lens is +2.5. Then its focal length is (a) 20 cm (b) 50 cm (c) 30 cm (d) 40 cm
Last Answer : Ans:(d)
Description : 17. A doctor has prescribed a corrective lens of power +1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging? -Physics-10
Last Answer : Power of lens (P) = 1/f P = 1.5D f = 1/1.5 = 10/15 = 0.66 m A convex lens has a positive focal length. Therefore, it is a convex lens or a converging lens.
Description : 16. Find the focal length of a lens of power -2.0 D. What type of lens is this? -Physics-10
Last Answer : Power of lens (P) = 1/f P = -2D f = -1/2 = -0.5 m A concave lens has a negative focal length. Therefore, it is a concave lens.
Description : 3. Find the power of a concave lens of focal length 2 m. -Physics-10
Last Answer : Focal length of concave lens (f) = 2 m Power of lens (P) = 1/f = 1/ (-2) = -0.5D
Description : The focal length of the lens in a photographic camera is 5 cm. What is the power of the lens? -Do You Know?
Last Answer : P=100/f (in cms) =100/5 1m= 100cm 0.2m= 20cm Hence,the power is 0.2 D The lens is convex as it is positive
Description : The focal length of a convex lens is 50 cm. what is its power? -Do You Know?
Last Answer : convex ( so focal length is positive ) given : f = 50cm or +50×10^-2m so find p =? formula p =1/f p = 1/50×10^-2 p= 100/50 P = 2
Description : What is the power of a lens if the focal length of a lens is + 0.1 m ?
Last Answer : If the focal length of a lens is + 0.1 m then the power of that lens will be p = 1 / f = 1 / 0.1 = 10 D [ here p power , f focus distance]
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 : 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 : Two thin lenses of power `+ 3 D and - 1 D` are held contact with each other. Focal length of the combination is :
Last Answer : Two thin lenses of power `+ 3 D and - 1 D` are held contact with each other. Focal length of the combination is :
Description : Dioptere is the unit of – (1) power of a lens (2) focal length of a lens (3) light intensity (4) sound intensity
Last Answer : (1) power of a lens
Description : The focal length of the lens in a photographic camera is 5 cm. What is the power of the lens?
Last Answer : + 20 D
Description : The focal length of a convex lens is 50 cm. what is its power?
Last Answer : +2 D
Description : Pick up the correct statement from the following: (A) The power of a lens is the reciprocal of its focal length (B) The unit of power of the lens is Diopter (C) The power of two or more thin lenses in contact is the power of the combination of the lenses (D) All the above
Description : Diopter is the power of a lens having a focal length of (A) 25 cm (B) 50 cm (C) 75 cm (D) 100 cm
Last Answer : (D) 100 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 : 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 : Suppose the power of a prescription lens is 4 diopters. What is the focal length of the lens?
Last Answer : ANSWER: = 25 CENTIMETERS