1 Answer

Answer :

The relationship between lens power and focus distance is: P = 1 / f .

Related questions

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 : A simple microscope consists of : (1) a short focus convex lens (2) a long focus convex lens (3) a short focus concave lens (4) a long focus concave lens

Last Answer : (1) a short focus convex lens Explanation: Simple microscope - light microscope consisting of a short focus single convex lens is used to produce an enlarged image. The magnifying glass was ... object viewed and one lens, increasing the visibility of the object by some amount (magnification).

Description : A simple microscope consists of : (1) a short focus convex lens (2) a long focus convex lens (3) a short focus concave lens (4) a long focus concave lens 

Last Answer :  a short focus convex lens

Description : Camera and Lens aperature and focus speed for a nature shot?

Last Answer : answer:Not enough info. What kind of equipment do you have? Not knowing anything else you want a fast shutter speed and fast lens.

Description : If I'm using a manual focus lens, does my far-sightedness mean that my pictures will be out of focus?

Last Answer : Just focus it until it’s as clear as it can be—it’s the best you can do.

Description : If someone dies with their eyes open does the lens still focus an image on the retina?

Last Answer : I’m sure it does until the brain stops being able to process that image.. making it a moot point.

Description : If a job requires extra fine engraving such as fonts below 6pts what focus lens is recommended.?

Last Answer : What is the answer ?

Description : Which one of the following can be used to focus sunlight? A. Plane mirror B. Concave lens C. Concave mirror D. Convex mirror

Last Answer : ANSWER: C

Description : Where will the image be formed if he shifts the candle towards the lens at a position of 35 cm? (a) At focus (b) Between focus and pole (c) At infinity (d) Between f 2 and f 1

Last Answer : (c) At infinity

Description : An object is placed beyond 2F, in front of a convex lens, image will be formed : (a) between F and 2F (b) at focus (c) at the centre of curvature (d) between focus and Optical centre

Last Answer : (a) between F and 2F

Description : Which of the following terms refers to the decrease in lens flexibility that occurs with age, resulting in the near point of focus getting farther away? a) Presbyopia Presbyopia usually begins in ... lens of the eye. d) Glaucoma Glaucoma is a disease characterized by increased intraocular pressure.

Last Answer : a) Presbyopia Presbyopia usually begins in the fifth decade of life, when reading glasses are required to magnify objects.

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 : How does a waveguide-type lens focus spherical wavefront microwave energy?

Last Answer : Some wavefronts are accelerated so that all wavefronts exit the lens at the same time

Description : In case of convex lens when the image formed is real, inverted and same size as the object then the object should have been at ______ position of lens. a) infinity b)focus c)2F d)between F and 2F

Last Answer : c)2F

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 : 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 : 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 : 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 : The measured distance from a lens to the object is 20 cm and from the lens to the image is 5 cm. Calculate the focal length

Last Answer : 1/4

Description : A 50 millimeter focal length camera lens photographs a 4 meter tall tree at a distance of 20 meters. How tall is the image of the tree?

Last Answer : ANSWER: 10 MILLIMETERS

Description : An object is located 1 meter in front of a converging lens having a focal length of 20 centimeters. At what distance behind the lens (whose thickness is negligible) will the image be formed? w) 18 centimeters x) 20 centimeters y) 22 centimeters z) 25 centimeters

Last Answer : ANSWER: Z -- 25 CENTIMETERS

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 : During accommodation: a. the distance between the lens and the ciliary body is decreased b. the tension in the suspensory ligament is increased c. the tension of the lens capsule is increased d. the refractive power of the lens is increased

Last Answer : the refractive power of the lens is increased

Description : Lens Power - What Does 2D Mean ?

Last Answer : The power of the lens -2D means the lens is concave and its focal length is 1/2 meter.

Description : What does lens power + 3D mean ?

Last Answer : The power of the lens + 3D means the lens is convex and its focal length is 1/3 meter.

Description : What is the SI unit of lens power ?

Last Answer : : The SI unit of lens power is 7 Radian / meter

Description : What is the power of a lens + 2D ?

Last Answer : If the power of a lens is + 2D then the lens is a convex lens. This is because the power of a convex lens is always positive (+).

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 : 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 : Suppose the power of a prescription lens is 4 diopters. What is the focal length of the lens?

Last Answer : ANSWER: = 25 CENTIMETERS

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 : power of a lens

Description : The parabola is defined mathematically as a curve generated by a point that moves suchthat its distance from the focus is always__________the distance to the directrix a.larger than b.smaller than c.equal to d.none of the above

Last Answer : c.equal to

Last Answer : Spherical Of the mirror Pole Point From Chief Focus Until At a distance Focus Distance Says.

Description : The distance between Pole and Focus is called a) principal axis b)focal length c)radius of curvature d)centre of curvature

Last Answer : b)focal length

Description : In a camera, the opening through which light enters the camera is called aperture. The distance between the closest and the farthest part of a view captured on a photograph, which is in focus, is ... field is not affected by the aperture size D. Larger the aperture, the larger the image captured 

Last Answer : A D

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 : 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 : 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 : 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 : 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 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.

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 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 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 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 : 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 ?