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

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
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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.
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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

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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 : 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

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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

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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

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

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

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.

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

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.

When a slide is placed 15 cm behind the lens in a projector, an image is formed at 3 infront of the lens. (i) Show the image formation by a ray diagra

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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

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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

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

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

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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

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

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

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

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

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

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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

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 

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

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

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

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.

A concave mirror of focal length 15 cm can form a magnified, erect as well as inverted image of an object placed in front of it." Justify this statement stating the position of the object with respect to the pole of the mirror in both the cases for obtaining the images. -Science

Description : A concave mirror of focal length 15 cm can form a magnified, erect as well as inverted image of an object placed in front of it." Justify this statement stating the position of the object with respect to the pole of the mirror in both the cases for obtaining the images. -Science

Last Answer : For magnified and erect image the object is placed between pole P and focus F. For magnified and inverted image the object is placed either at focus or anywhere between F and C.

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

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.

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

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Last Answer : a) convex lens

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

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

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Vehicles use ______ to see the objects coming from behind. (1) Concave lens (2) Convex lens (3) Convex mirror (4) Concave mirror

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Vehicles use _____ to see the objects coming from behind. (1) Concave lens (2) Convex lens (3) Convex mirror (4) Concave mirror

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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 a concave mirror (iii) in front of a convex mirror (iv) at 2F of a convex lens (v) in front of a concave lens -Physics

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.

A concave lens can form a real and inverted image, when : (a) Object is placed at 2f (b) Object is placed beyond 2f (c) Object is placed between f and 2f (d) It can never form a real and

Description : A concave lens can form a real and inverted image, when : (a) Object is placed at 2f (b) Object is placed beyond 2f (c) Object is placed between f and 2f (d) It can never form a real and

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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

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

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A travelling microscope is focussed on a mark made on a paper. When a slab of `1.45cm` thickness is placed on the marl, the microscope has to be raise

Description : A travelling microscope is focussed on a mark made on a paper. When a slab of `1.45cm` thickness is placed on the marl, the microscope has to be raise

Last Answer : A travelling microscope is focussed on a mark made on a paper. When a slab of `1.45cm` ... the mark again. Calculate the refractive index of glass.

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

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.

A compound lens is made of two lenses having powers `+15.5 D` and `-5.5D`. An object of 3cm height is placed at a distance of 30 cm from this compound

Description : A compound lens is made of two lenses having powers `+15.5 D` and `-5.5D`. An object of 3cm height is placed at a distance of 30 cm from this compound

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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 : 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 ?

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

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.

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

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.

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

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.

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) =

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`.

2. A concave mirror produces three times magnified (enlarged) real image of an object placed at 10 cm in front of it. Where is the image located? -Physics-10

Description : 2. A concave mirror produces three times magnified (enlarged) real image of an object placed at 10 cm in front of it. Where is the image located? -Physics-10

Last Answer : Magnification produced by a spherical mirror: Object distance (u) = – 10 cm v = 3 × (- 10) = – 30 cm Therefore, the negative sign indicates that an inverted image is formed in front of the given concave mirror at a distance of 30 cm.

An object is placed at a distance of 12 cm in front of a concave mirror of radius of curvature 30 cm. List four characteristics of the image formed by the mirror. -Science

Description : An object is placed at a distance of 12 cm in front of a concave mirror of radius of curvature 30 cm. List four characteristics of the image formed by the mirror. -Science

Last Answer : Here, radius of curvature of concave mirror, R = 30 cm. Therefore, focal length of the mirror, f = R/2 = 30/2 = 15 cm Also, object distance, u = 12 cm Hence, knowing the focal length of mirror and ... (i) Erect (ii) Larger in size than that of the object (iii) Virtual and (iv) Behind the mirror.

A concave mirror forms a real image four times as tall as the object placed 10 cm infront of mirror. Find the position of the image and the radius of

Description : A concave mirror forms a real image four times as tall as the object placed 10 cm infront of mirror. Find the position of the image and the radius of

Last Answer : A concave mirror forms a real image four times as tall as the object placed 10 cm infront of ... image and the radius of curvature of the mirror.

Find the position of an object which when placed in front of a concave mirror of focal length 20 cm, produces a virtual image which is twice the size

Description : Find the position of an object which when placed in front of a concave mirror of focal length 20 cm, produces a virtual image which is twice the size

Last Answer : Find the position of an object which when placed in front of a concave mirror of focal length 20 cm ... image which is twice the size of the object.

A dentist concave mirror has a radius of curvature of `30 cm`. How far must it be placed from a small cavity in order to get a virtual image magnified

Description : A dentist concave mirror has a radius of curvature of `30 cm`. How far must it be placed from a small cavity in order to get a virtual image magnified

Last Answer : A dentist concave mirror has a radius of curvature of `30 cm`. How far must it be placed from a ... order to get a virtual image magnified `5` times ?

A candle flame 2 cm high is palced at distance of 2 metere from a wall. How far from the wall must a concave mirror to placed in order to form an imag

Description : A candle flame 2 cm high is palced at distance of 2 metere from a wall. How far from the wall must a concave mirror to placed in order to form an imag

Last Answer : A candle flame 2 cm high is palced at distance of 2 metere from a wall. How far from the wall must ... an images of the flame 6 cm high on the wall ?

An object is placed in front of a concave mirror of radius of curvature `40 cm` at a distance of `10 cm`. Find the position, nature and magnification

Description : An object is placed in front of a concave mirror of radius of curvature `40 cm` at a distance of `10 cm`. Find the position, nature and magnification

Last Answer : An object is placed in front of a concave mirror of radius of curvature `40 cm` at a ... Find the position, nature and magnification of the image.

If a lens can converge the sun rays at a point 20 cm. away from its optical centre, the power of this lens is — (a) + 2D (b) - 2D (c) + 5D (d) - 51D

Description : If a lens can converge the sun rays at a point 20 cm. away from its optical centre, the power of this lens is — (a) + 2D (b) - 2D (c) + 5D (d) - 51D

Last Answer : (c) + 5D

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

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,

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 the image formed if the object is 2 cm high? With the help of a ray diagram show the formation of the image by the lens in this case. -Physics

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:

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 convex lens and size of the image formed on the screen? Draw a ray diagram to show the formation of the image in this position of the object with respect to the lens. -Physics

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.

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

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 ?

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

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.

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

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.

Where should an object be placed from a converging lens of focal length 20 cm, so as to obtain a real image of magnification 2?

Description : Where should an object be placed from a converging lens of focal length 20 cm, so as to obtain a real image of magnification 2?

Last Answer : Where should an object be placed from a converging lens of focal length 20 cm, so as to obtain a real image of magnification 2?

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 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)`.

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 image on the screen. (a) In which direction does he move the lens to focus the flame on the screen? (b) What happens to the size of the image of the flame formed on the screen? (c) What difference is seen in the intensity (brightness) of the image of the flame on the screen? (d) What is seen on the screen when the flame is very close (at about 5 cm) to the lens?

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.