How can a convex lens light a matxhstick if held towards the sun?

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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 : 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 : 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 : A small hole in the window of a closed room forms an inverted image of outside building on the opposite wall of the room. This happens because (a) the rays of light suffer lateral inversion on entering the ... propagation of light (c) the hole acts as a convex lens (d) the hole acts as a prism

Last Answer : Ans:(b)

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 : 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 : 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 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 : In Fresnel diffraction A. source of light is kept at infinite distance from the aperture B. source of light is kept at finite distance from the aperture C. Convex lens used D. aperture width is selected so that it can acts as a point source

Last Answer : B. source of light is kept at finite distance from the aperture

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 : 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 : The following are true about the lens: a. the anterior capsule is 10 times thicker than the posterior capsule b. the anterior surface has a greater radius of curvature than the posterior surface c ... the cornea d. the lens is more effective in absorbing light with long than short wave-lengths

Last Answer : during accommodation the lens moves towards the cornea

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 : 12. Draw ray diagrams to represent the nature, position and relative size of the image formed by a convex lens for the object placed: -Chemistry-10

Last Answer : Answer. hope this helps you

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 : 9. One-half of a convex lens is covered with a black paper. Will this lens produce a complete image of the object? Verify your answer experimentally. Explain your observations. -Physics-10

Last Answer : Yes, it will produce a complete image of the object, as shown in the figure. This can be verified experimentally by observing the image of a distant object like a tree on a screen when the ... the lens is covered with a black paper. However, the intensity or brightness of the image will reduce.

Description : 3. Where should an object be placed in front of a convex lens to get a real image of the size of the object? -Physics-10

Last Answer : (b) The object should be placed at twice the focal length

Description : 2. A convex lens forms a real and inverted image of a needle at a distance of 50 cm from it. Where is the needle placed in front of the convex lens if the image is equal to the size of the object? -Physics-10

Last Answer : The position of the image should be at 2F since the image is the real and same size. It is given that the image of the needle is formed at a distance of 50 cm from the convex lens. Therefore, the needle is ... (u) = - 50 cm Image distance, (v) = 50 cm Focal length = f According to the lens formula,

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 : 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 a convex lens ?

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

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 : What is the way to recognize convex lens ?

Last Answer : To easily recognize a lens, you have to place a finger very close to the lens and look at it from the other side. If the reflection is congruent and larger in size than the object, then the lens is convex.

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 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 : The distance between a convex lens and a plane mirror is 15 cm. The parallel rays incident on the convex lens, after reflection from the mirror, form

Last Answer : The distance between a convex lens and a plane mirror is 15 cm. The parallel rays incident on the ... and find out the focal length of the lens.

Description : An object is placed at a distance of `1.5 m` from a screen and a convex lens is interposed between them. The magnification produced is `4`. What is th

Last Answer : An object is placed at a distance of `1.5 m` from a screen and a convex lens is interposed between ... `4`. What is the focal length of the lens ?

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 : A convex lens is placed on an optical bench and is moved till it gives a real image of an object at a minimum distance of 80 cm from the latter. Find

Last Answer : A convex lens is placed on an optical bench and is moved till it gives a real image of an object ... cm from the lens, find the position of the image.

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 : The power of a thin convex lens of glass is `5 dioptre`. When it is immersed in a liquid of refractive index `mu`, it behave like a diverging lens of

Last Answer : The power of a thin convex lens of glass is `5 dioptre`. When it is immersed in a liquid of refractive index ... liquid, if `mu` of glass `= 3//2`.

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 what distance must an object be placed from convex lens of power 4D to obtain a real image three times the size of the object ?

Last Answer : A what distance must an object be placed from convex lens of power 4D to obtain a real image three times the size of the object ?

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 : 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 : The radii of curvatureof double convex lens of glass `(mu = 1.5)` are in the ratio of `1 : 2`. This lens renders the rays parallel coming from an illu

Last Answer : The radii of curvatureof double convex lens of glass `(mu = 1.5)` are in the ratio of `1 ... 6 cm`. Calculate the radii of curvature of its surfaces.

Description : The radii of curvature of each surface of a convex lens is `20 cm` and the refractive index of the material of the lens is `3//2` (i) Calculate its fo

Last Answer : The radii of curvature of each surface of a convex lens is `20 cm` and the refractive index of the ... What happens if the lens is cut along `CD` ?

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 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 convex lens of refractive index 1.5 is immersed in a liquid of refractive index (i) 1.6 (ii) 1.3 and (iii) 1.5. what changes happens to the focal le

Last Answer : A convex lens of refractive index 1.5 is immersed in a liquid of refractive index (i) 1.6 (ii) ... the focal length of the lens in the three cases ?

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 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 : 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 : 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 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.