In the diagram shows below rays are coming from infinity and after passing through both the lenses meet on a screen placed at a distance of 30 cm from

In the diagram shows below rays are coming from infinity and after passing through both the lenses meet on a screen placed at a distance of 30 cm from
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In the diagram shows below rays are coming from infinity and after passing through both the lenses ... Calculate the focal length of the concave lens.
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The radius of curvature of a converging mirror is 30 cm. At what distance from the mirror should an object be placed so as to obtain a virtual image? (a) infinity (b) 30 cm (c) Between 16 cm and 30 cm (d) Between 0 cm and 15 cm

Description : The radius of curvature of a converging mirror is 30 cm. At what distance from the mirror should an object be placed so as to obtain a virtual image? (a) infinity (b) 30 cm (c) Between 16 cm and 30 cm (d) Between 0 cm and 15 cm

Last Answer : (d) Between 0 cm and 15 cm

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

Last Answer : A compound lens is made of two lenses having powers `+15.5 D` and `-5.5D`. An object of ... cm from this compound lens. Find the size of the image.

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.

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.

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

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) The distance between the diaphragm and the front lens of the eyepiece is kept equal to 1/4 th of the focal length of a lens so that rays from a point on the diaphragm enter the eye as a parallel beam (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 

Last Answer : (D) All the above 

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:

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.

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

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.

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

Two light sources of intensities 8 cd and 12 cd are placed on the same side of a photometer screen at a distance of 40 cm from it. Where should a 80 c

Description : Two light sources of intensities 8 cd and 12 cd are placed on the same side of a photometer screen at a distance of 40 cm from it. Where should a 80 c

Last Answer : Two light sources of intensities 8 cd and 12 cd are placed on the same side of a photometer ... 80 cd source be placed to balance the illuminance ?

Which of the following condition is essential for observing Fraunhofer diffraction? A. Source must be close to slit and screen should be at infinite distance B. Both source and screen must be close to slit C. Source must be at infinity and screen should be close to the slit D. Both source and screen must be at infinity

Description : Which of the following condition is essential for observing Fraunhofer diffraction? A. Source must be close to slit and screen should be at infinite distance B. Both source and screen must be close to ... infinity and screen should be close to the slit D. Both source and screen must be at infinity

Last Answer : D. Both source and screen must be at infinity

An object is placed at a distance equal to the focal length of convex mirror. If the focal length of the mirror be f, then the distance of the image from the pole of the mirror is (a) Less than f (b) Equal of f (c) More than f (d) Infinity

Description : An object is placed at a distance equal to the focal length of convex mirror. If the focal length of the mirror be f, then the distance of the image from the pole of the mirror is (a) Less than f (b) Equal of f (c) More than f (d) Infinity

Last Answer : Ans:(a)

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.

If a suspended body is struck at the centre of percussion, then the pressure on die axis passing through the point of suspension will be (A) Maximum (B) Minimum (C) Zero (D) Infinity

Description : If a suspended body is struck at the centre of percussion, then the pressure on die axis passing through the point of suspension will be (A) Maximum (B) Minimum (C) Zero (D) Infinity

Last Answer : (C) Zero

14. An object 5 cm is placed at a distance of 20 cm in front of a convex mirror of radius of curvature 30 cm. Find the position, nature and size of the image. -Physics-10

Description : 14. An object 5 cm is placed at a distance of 20 cm in front of a convex mirror of radius of curvature 30 cm. Find the position, nature and size of the image. -Physics-10

Last Answer : Object distance (u) = - 20 cm Object height (h) = 5 cm Radius of curvature (R) = 30 cm Radius of curvature = 2 Focal length R = 2f f = 15 cm According to the mirror formula, ... image height indicates that the image formed is erect. Hence, the image formed is erect, virtual, and smaller in size.

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.

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

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

Sumati did some preliminary experiment with the lenses and found out that the magnification of the eyepiece (L 2 ) is 3. If in her experiment with L 2 she found an image at 24 cm from the lens, at what distance did she put the object? (a) 72 cm (b) 12 cm (c) 8 cm (d) 6 cm

Description : Sumati did some preliminary experiment with the lenses and found out that the magnification of the eyepiece (L 2 ) is 3. If in her experiment with L 2 she found an image at 24 cm from the lens, at what distance did she put the object? (a) 72 cm (b) 12 cm (c) 8 cm (d) 6 cm

Last Answer : (c) 8 cm

Pulverised coal passing through 200 mesh screen has a diameter of 0.074 mm (74 micron). The same passing through 50 mesh screen will have a dia of __________ mm. (A) 0.007 (B) 0.30 (C) 50 (D) 0.014

Description : Pulverised coal passing through 200 mesh screen has a diameter of 0.074 mm (74 micron). The same passing through 50 mesh screen will have a dia of __________ mm. (A) 0.007 (B) 0.30 (C) 50 (D) 0.014

Last Answer : (B) 0.30

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

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.

Two thin lenses of focal lengths 15 cm and 30 cm resepectively are kept in contact with each other. What is the power of the combined system?

Description : Two thin lenses of focal lengths 15 cm and 30 cm resepectively are kept in contact with each other. What is the power of the combined system?

Last Answer : Two thin lenses of focal lengths 15 cm and 30 cm resepectively are kept in contact with each other. What is the power of the combined system?

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 

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

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

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.

Fresnel’s type diffraction is observed when __________. A. Only screen is placed at finite distance B. Only source is placed at finite distance C. Both source and screen are at finite distance D. Neither source nor screen is at finite distance

Description : Fresnel’s type diffraction is observed when __________. A. Only screen is placed at finite distance B. Only source is placed at finite distance C. Both source and screen are at finite distance D. Neither source nor screen is at finite distance

Last Answer : C. Both source and screen are at finite distance

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

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.

A ........ is an initial document that shows where all text and graphic elements will be placed A. Comp B. DTP C. On screen D. Online

Description : A ........ is an initial document that shows where all text and graphic elements will be placed A. Comp B. DTP C. On screen D. Online

Last Answer : C. On screen

A squid axon is placed on stimulating electrodes, and an intracellular electrode is inserted and connected through a cathode-ray oscilloscope (CRO) to an indifferent electrode. When the axon is stimulated, the latent period is 1.5 ms. The intracellular electrode is 6 cm form the anode of the simulator and 4.5 cm from the cathode of the simulator. What is the conduction velocity of the axon. a. 15 m/s b. 30 m/s c. 40 m/s d. 67.5 m/s e. This cannot be determined from the information given

Description : A squid axon is placed on stimulating electrodes, and an intracellular electrode is inserted and connected through a cathode-ray oscilloscope (CRO) to an indifferent electrode. When the axon is stimulated, the latent ... . 40 m/s d. 67.5 m/s e. This cannot be determined from the information given

Last Answer : 30 m/s

Non-passing sight distance along a road is the longest distance at which the driver of a moving vehicle, may see an obstacle on the pavement (A) 10 cm high (B) 25 cm high (C) 50 cm high (D) 100 cm high

Description : Non-passing sight distance along a road is the longest distance at which the driver of a moving vehicle, may see an obstacle on the pavement (A) 10 cm high (B) 25 cm high (C) 50 cm high (D) 100 cm high

Last Answer : Answer: Option A

The setting sun often looks oval in the shape because of-----? A. The fact that sun really becomes oval in the evening B. Refraction of rays of sun passing through the atmosphere (Answer) C. Optical Illusion D. Dispersion

Description : The setting sun often looks oval in the shape because of-----? A. The fact that sun really becomes oval in the evening B. Refraction of rays of sun passing through the atmosphere (Answer) C. Optical Illusion D. Dispersion

Last Answer : B. Refraction of rays of sun passing through the atmosphere (Answer)

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 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 square loop of side and a straight infinity conducor are placed in the same plane with two sides of the squre parallel to the conductor. The resista

Description : A square loop of side and a straight infinity conducor are placed in the same plane with two sides of the squre parallel to the conductor. The resista

Last Answer : A square loop of side and a straight infinity conducor are placed in the same plane with two sides of the squre ... na+b)/(b)|`. Find the value of n.

If charge is placed at infinity, it's potential is A. zero B. infinite C. 1 D. -1

Description : If charge is placed at infinity, it's potential is A. zero B. infinite C. 1 D. -1

Last Answer : zero

An object is placed at focus of a concave mirror, image will be formed at : (a) focus (b) between F and C (c) beyond C (d) at infinity

Description : An object is placed at focus of a concave mirror, image will be formed at : (a) focus (b) between F and C (c) beyond C (d) at infinity

Last Answer : (d) at infinity

For a test charge placed at infinity, the electric field will be a) Unity b) +∞ c) Zero d) -∞

Description : For a test charge placed at infinity, the electric field will be a) Unity b) +∞ c) Zero d) -∞

Last Answer : c) Zero

In screen analysis, the notation +5 mm/-10 mm means particles passing through (A) 10 mm screen and retained on 5 mm screen (B) 5 mm screen and retained on 10 mm screen (C) Both 5 mm and 10 mm screens (D) Neither 5 mm nor 10 mm screen

Description : In screen analysis, the notation +5 mm/-10 mm means particles passing through (A) 10 mm screen and retained on 5 mm screen (B) 5 mm screen and retained on 10 mm screen (C) Both 5 mm and 10 mm screens (D) Neither 5 mm nor 10 mm screen

Last Answer : (A) 10 mm screen and retained on 5 mm screen

A conductor of length L has current I passing through it, when it is placed parallel to a magnetic field. The force experienced by the conductor will be (a) zero (b) BLI (c) B2LI (d) BLI2

Description : A conductor of length L has current I passing through it, when it is placed parallel to a magnetic field. The force experienced by the conductor will be (a) zero (b) BLI (c) B2LI (d) BLI2

Last Answer : (a) zero

A conductor of length L has current I passing through it, when it is placed...

Description : A conductor of length L has current I passing through it, when it is placed parallel to a magnetic field. The force experienced by the conductor will be

Last Answer : A conductor of length L has current I passing through it, when it is placed parallel to a magnetic field. The force experienced by the conductor will be zero.

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

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 ?

An object of `1cm^(2)` face area is placed at a distance of 1.5m from a screen. How far from the object should a concave mirror be placed so that it f

Description : An object of `1cm^(2)` face area is placed at a distance of 1.5m from a screen. How far from the object should a concave mirror be placed so that it f

Last Answer : An object of `1cm^(2)` face area is placed at a distance of 1.5m from a screen. How ... the screen? Also, calculate the focal length of the mirror.

Fraunhofer diffraction is observed when __________. A. Only screen is placed at finite distance B. source is placed at finite distance C. neither source nor screen is at finite distance D. None of these

Description : Fraunhofer diffraction is observed when __________. A. Only screen is placed at finite distance B. source is placed at finite distance C. neither source nor screen is at finite distance D. None of these

Last Answer : D. None of these

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

12. An object is placed at a distance of 10 cm from a convex mirror of focal length 15 cm. Find the position and nature of the image. -Physics-10

Description : 12. An object is placed at a distance of 10 cm from a convex mirror of focal length 15 cm. Find the position and nature of the image. -Physics-10

Last Answer : Focal length of convex mirror (f) = +15 cm Object distance (u) = - 10 cm According to the mirror formula, The image is located at a distance of 6 cm from the mirror on the other ... and a value of less than 1 of magnification indicates that the image formed is virtual and erect and diminished.

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 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.