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 : 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 : 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 : A convex lens of focal length 30 cm is placed between a screen and a square plate of area `4cm^(2)`. The image of the plate formed on the screen is `1
Last Answer : A convex lens of focal length 30 cm is placed between a screen and a square plate of area ... Calculate the distance between the plate and the screen.
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 : A student focuses the image of a candle flame, placed at about 2 m from a convex lens of focal length 10 cm, on a screen. After that he moves gradually the flame towards the lens and each time focuses its ... d) What is seen on the screen when the flame is very close (at about 5 cm) to the lens?
Last Answer : (a) The student moves the lens away from the screen to focus the image because on moving the candle towards the lens, the image distance increases. (b)The size of the image increases when the object ... on the screen. A virtual image is formed behind the candle on the same side of the screen.
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
Last Answer : (D) All the above
Description : 1. A concave lens has focal length of 20 cm. At what distance from the lens a 5 cm tall object be placed so that it forms an image at 15 cm from the lens? Also calculate the size of the image formed. [Delhi] -Chemistry-10
Last Answer : Answer. hope this helps youu
Description : A concave lens has focal length of 20 cm. At what distance from the lens a 5 cm tall object be placed so that it forms an image at 15 cm from the lens? Also calculate the size of the image formed. -Physics
Last Answer : Answer. I hope it helped you.
Description : 15. 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 is formed on the screen. What is the focal length of the conve -Chemistry-10
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 : 2. 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. [All India] -Chemistry-10
Last Answer : this is the answer for the respected question
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
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 : The focal length of a convex lens of glass `(mu = 1.5)` in air is 30 cm. Find its focal length when the lens is placed in water `(mu = 4//3)`.
Last Answer : The focal length of a convex lens of glass `(mu = 1.5)` in air is 30 cm. Find its focal length when the lens is placed in water `(mu = 4//3)`.
Description : The radii of curvature of a double convex lens are 30 cm and 60 cm and its refractive index is 1.5. calculate its focal length.
Last Answer : The radii of curvature of a double convex lens are 30 cm and 60 cm and its refractive index is 1.5. calculate its focal length.
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 : 11. A concave lens of focal length 15 cm forms an image 10 cm from the lens. How far is the object placed from the lens? Draw the ray diagram. -Physics-10
Last Answer : Focal length of concave lens (OF1), f = – 15 cm Image distance, v= – 10 cm According to the lens formula, The negative value of u indicates that the object is placed 30 cm in front of the lens. This is shown in the following ray diagram.
Description : A concave lens focal length 10 cm is placed on the axis of concave mirror of 10 cm radius at a distance of 5 cm from the mirror. An object is placed s
Last Answer : A concave lens focal length 10 cm is placed on the axis of concave mirror of 10 cm radius ... the object itself. Determine the position of the object.
Description : The two surfaces of a double concave lens are of curvature 10 cm and 40 cm. Find the focal length of the lens in water. The refractive index of water
Last Answer : The two surfaces of a double concave lens are of curvature 10 cm and 40 cm. Find the focal length of ... and that of the lens of the material is 3/2.
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 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 : A needle 10 cm long is placed along the axis of a convex lens of focal length 10 cm such that the middle point of the neddle is at a distance of 10 cm
Last Answer : A needle 10 cm long is placed along the axis of a convex lens of focal length 10 cm such that ... lens. Find the length of the image of the neddle.
Description : A source of light and a screen are placed 90 cm apart. Where should a convex lens of 20 cm focal length be placed in order to form a real image of the
Last Answer : A source of light and a screen are placed 90 cm apart. Where should a convex lens of 20 cm focal ... form a real image of the source on the screen ?
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 : 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 : A double convex lens has radii 20 cm. The index of refraction of glass is 1.5. Compute the focal length of this lens in air and when immersed in carbo
Last Answer : A double convex lens has radii 20 cm. The index of refraction of glass is 1.5. Compute ... immersed in carbon disulphide of refractive index 1.63.
Description : The focal length of a convex lens is 50 cm. what is its power?
Last Answer : +2 D
Description : 1. The focal length of a convex lens is 50 cm. what is its power? 2. Among the Indian languages, which one is spoken maximum in the world after Hindi? 3. Which formulates fiscal policy? 4. ... Sun (in million kms.)? 20. Upanishads, also known as the Vedantas, are How many are these upanishads?
Last Answer : Answer : 1. +2 D 2. Bengali 3. Finance Ministry 4. China-Pakistan5. Lord Ellenborough 6. Leaf 7. Advocate General 8. Lithium and osmium 9. Chenab 10. Indigo 11. Canada 12. The Mellanesia 13. Leaf 14. Black 15. Atharvaveda 16. President 17. Roentgens 18. Third Plan 19. 149 20. 108
Description : A sphere of 1 cm radius is placed at the distance of 50 cm from the convex lens of 10 cn focal length. What would be the height of the image of sphere ?
Last Answer : 0.5cm
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 : 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 : 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 : 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 : 14. An object 2 cm in size is placed 30 cm in front of a concave mirror of focal length 15 cm. At what distance from the mirror should a screen be placed in order to obtain a sharp image? What will be the nature and the size of the -Chemistry-10
Last Answer : Answer. hope this helps you
Description : At what distance should an object be placed from a convex lens of focal langth `15 cm` to obtain an image three times the size of the object ?
Last Answer : At what distance should an object be placed from a convex lens of focal langth `15 cm` to obtain an image three times the size of the object ?
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 : 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 a double convex lens is equal to radius of curvature of either surface. The refractive index of its material is
Last Answer : The focal length of a double convex lens is equal to radius of curvature of either surface. The refractive index of its material is
Description : An object is placed at `0.06` m from a convex lens of focal length `0.1`m. Calculate the position of the image?
Last Answer : An object is placed at `0.06` m from a convex lens of focal length `0.1`m. Calculate the position of the image?
Description : If f1 and f2 are the distances from the optical centre of a convex lens of focal length to conjugate two points P1 and P2 respectively, the following relationship holds good (A) f = f1 + f2 (B) f = ½ (f1 + f2) (C) 1/f = 1/f1 + 1/f2 (D) None of these
Last Answer : (C) 1/f = 1/f1 + 1/f2
Description : 10. An object 5 cm in length is held 25 cm away from a converging lens of focal length 10 cm. Draw the ray diagram and find the position, size and the nature of the image formed. -Physics-10
Last Answer : Height of the Object, h0 = 5 cm Distance of the object from converging lens, u = -25 cm Focal length of a converging lens, f = 10 cm Using lens formula, Thus, the image is inverted and formed at a distance of 16.7 cm behind the lens and measures 3.3 cm. The ray diagram is shown below.
Description : A converging lens forms a three times magnified image of an object, which can be take on a screen. If the focal length of the lens is 30 cm, then the distance of the object from the lens is (a) - 55 cm (b) - 50 cm (c) - 45 cm (d) - 40 cm
Last Answer : (d) - 40 cm
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 : 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 : Find the size, nature and position of image formed by a concave mirror, when an object of size 1 cm is placed at a distance of 15 cm. Given focal leng
Last Answer : Find the size, nature and position of image formed by a concave mirror, when an object of size 1 cm ... 15 cm. Given focal length of mirror is 10 cm.
Description : 15. An object of size 7.0 cm is placed at 27 cm in front of a concave mirror of focal length 18 cm. At what distance from the mirror should a screen be placed so that a sharply focused image can be obtained? Find the size and nature of the image. -Physics-10
Last Answer : Object distance (u) = – 27 cm Object height (h) = 7 cm Focal length (f) = – 18 cm According to the mirror formula, The negative value of image height indicates that the image formed is inverted.