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## How to find out the radius of curvature of a covex lens when focal length is given?

Asked by 12th March 2008 9:13 PM

## Q.On a convex lens ,light of red and violet colour is incident separately , then how does the focal length of lens change?

Asked by Ravi consul 4th March 2015 6:48 PM

## the distance between a convex lens and a plane mirror is 10 cm.The parallel rays incidenton the convex lens after reflection from the mirror form an image at the optical centre of the lens.Find the focal length of the lens

Asked by dev.sultanpur123 1st June 2015 12:52 AM

## I got to knew that when light passes through the optical centre, then it bent , but as the lens is very thin , this bent is negligible and thus we neglect it but when other rays passes through the lens(except optical centre) then why does they bent more?lens is thin so why should'nt we neglect it too??

Asked by jgprmr 17th June 2017 12:38 AM

## When light travels in direction of optical centre of convex lens , it suffers very very slight deviation .....so from this, is it correct to conclude that such light rays/waves which are trevelling in direction of optical centre are actually travelling along the normal?explain

Asked by jgprmr 17th June 2017 9:25 PM

## If the image formed in cinema is real then shouldn't it be inverted, and how do they avoid it?

Asked by nileshpatel19752000 13th October 2017 11:52 PM

## Give me crct solution with clear explanation

Asked by venkat 8th November 2017 6:26 PM

## A LUMINOUS OBJECT IS PLACED AT A DISTANCE OF 30CM FROM THE CONVEX LENS OF FOCAL LENGTH 20CM.ON THE OTHER SIDE OF THE LENS,AT WHAT DISTANCE FROM THE LENS A CONVEX MIRROR OF RADIUS OF CURVATURE 10CM BE PLACED IN ORDER TO HAVE AN UPRIGHT IMAGE OF THE OBJECT COINCIDENT WITH IT?A-12CM,B-30CM,C-50CM,D-70CM

Asked by Priyanka 13th November 2017 4:04 PM

## an object is placed at a distance of f/2 from a concavex lens. The image will be? A-at 3f/2,real and Inverted.B-at 2f virtual and erect. C-at f real and inverted. D-at one of the foci virtual and double size.

Asked by Priyanka 13th November 2017 9:35 PM

## A Plano convex lens of refractive index=1.5,silverd at the convex surface behave as an concave mirror of f=20cm.what is the radius of curvature of curved surface? Options are 40cm,20,60,30all in cm

Asked by Priyanka 13th November 2017 9:39 PM

## Astronomical telescope has two lens of focal power 0.5D,and 20D.its magnifying power is? 1-40cm,2-10cm,3-100cm,4-35cm

Asked by Priyanka 15th November 2017 9:16 AM

## A student performed an experiment with convex lens and found the virtual image of an object.  Find : (a) Position of the object.  (b) Draw ray diagram for the above situation.

Asked by pdcavita 11th December 2017 12:19 PM

## A student focuses the image of a well illuminated distant object on a screen using a convex lens. After that he gradually moves the object towards the lens and each time focuses its image on the screen by adjusting the lens.  a)  In which direction - towards the screen or away from the screen, does he move the lens?  b) What happens to the image on the screen when he moves the object very close to the lens?

Asked by pdcavita 19th December 2017 6:43 AM

## A student focuses the images of a well illuminated distant object on a screen using a convex lens. After that he gradually moves the object towards the lens and each time focuses its image on the screen by adjusting the lens.  (¡) what happens to the size of the image - does it decrease or increase?

Asked by pdcavita 20th December 2017 6:15 PM

## If a convex lens iis enlongated , then how the focal length and thickness will decrease or increse?what is curvature in lens here?

Asked by sucharitasahoo1 24th December 2017 12:52 AM

## A SCREEN IS PLACED 90 CM FROM AN OBEJCT. THE IMAGE OF THE OBJECT ON THE SCREEN IS FORMED BY A CONVEX LENS AT TWO DIFFERENT LOCATIONS SEPARATED BY 30 CM. FIND THE FOCAL LENGTH OF THE LENS.

Asked by sohamsouthpoint02 30th December 2017 1:28 AM

## a convex lens of focal length f is cut into two halves such that one surface of each is plane what is the focal length of each half

Asked by deepakphy93 3rd January 2018 1:08 PM

## Calculate the minimum dist. between object and its real image formed by convex lens of focal length F

Asked by gpnkumar0 5th January 2018 8:41 PM

## How to find the focal length of combination of lens

Asked by lovemaan5500 7th January 2018 6:58 AM

## Which type of lens is used in projector?

Asked by Somenathdewanji2050 29th January 2018 7:11 AM

## A biconvex lens made of  a transparent medium of n=1.5 is immetrsed in a medium of n=1.33.will the lens behave converging or diverging?give reason.

Asked by vasturushi 1st February 2018 9:46 PM

## A convex lens is placed in contact with a plane mirror. a point object is placed 20cm on the axis of the combination has its image coincideing with itself.what is the focal length of the lens?

Asked by vasturushi 1st February 2018 9:50 PM

## Can you give me the explanation

Asked by gpnkumar0 4th February 2018 9:34 PM

## pls solve it

Asked by gpnkumar0 4th February 2018 9:41 PM

## how can we identtify lens without touching it

Asked by janibirwa1 18th February 2018 12:00 PM

## A screen is placed at a distance of 100 cm from an object. The image of the object isformed on the screen by a convex lens for two different locations of the lens separated by 20 cm. Calculate the focal length of the lens used.

Asked by Raj 20th February 2018 5:54 AM

## Dera sir, please explain the displacement method to find the focal length of the convex lens in detail

Asked by modi72879 22nd February 2018 10:03 PM

## A point object O is kept at a distance of 30 cm of a convex lens power +4D towards its left.It is observed that when a convex mirror is kept on the right side at a distance of 50 cm of the convex lens ,the image of the object O formed by the lens mirror combination with the object itself.Calculate the focal length of the convex mirror.

Asked by Balbir 25th February 2018 11:32 AM

## PLS EXPLAIN

Asked by gpnkumar0 14th March 2018 9:17 PM

## plz solve the question with explanation

Asked by futureisbright051101 11th April 2018 6:48 AM

## Q. 3

Asked by Rayeesa 25th April 2018 9:55 PM

## Q. 4

Asked by Rayeesa 25th April 2018 9:57 PM

## Q. 5

Asked by Rayeesa 25th April 2018 9:59 PM

## Q. 6

Asked by Rayeesa 25th April 2018 10:00 PM

## A magnifying lens of focal length of 20 cm is held 10 cm away from the object 0.25 cm l9ng. Find the position, nature of the image, power and magnification of the lens.

Asked by lakhinandanbora21590 11th July 2018 11:35 PM

## A concave lens produces an image 20cm from the lens of an object placed 30cm form the lens calculate the power of the lens

Asked by Satish.ouc 15th July 2018 10:21 AM

## Q1:Where should an object be placed in front of a convex lens of focal length 0.12 m to obtain a real image of size three times the size of the of the object,on the screen? Q2:A convex lens forms an inverted image of size same as that of the object which is placed at a distance 60 cm in front of the lens.Find:a.The position of the image and b.The focal length of the lens. Q3:A concave lens forms an erect image of 1/3rd size of the object which is placed at a distance 30 cm in front of the lens.Find:a.The position of the image and b.The focal length of the lens.

Asked by kaursukhjindersukh 3rd September 2018 10:38 PM

## what this

Asked by krishdabhoya2003 22nd September 2018 7:50 PM

## 1. Why do light rays passing through optical centre of lens experiences no deviation?  2. Why it is harmful to look at the sun through convex lens?

Asked by agraharianiruddha 5th October 2018 6:14 PM

## how can we identify the lenses experimentally

Asked by abhishekayush15 11th November 2018 10:15 AM

## how can we find the focal length of a mirror or lenses

Asked by abhishekayush15 11th November 2018 10:17 AM

## electronic technician use .............. lens

Asked by rohitmotkar 27th November 2018 11:06 AM

## Distinguish between concave and convex lens

Asked by sangeeta735200 13th December 2018 7:52 PM

## An object placed on ameter scale at 8 cm mark was focused on a white screen placed at 92 cm mark,using a converginglens placed on the meter scale at 50 cm mark. a)  find the focal length of the converging lens b) find the position of the image formed if the object is shifted towards the lens at a position of 29 cm c) state the nature of image formed if the object is further shifte towards the lens.

Asked by rs1702 7th January 2019 12:09 PM

## The numerical value of the focal length of a thing convergent lens is f and an object is at a distance of  u from the lens ; a plane mirror is placed behind the lens perpendicular to the axis at a distance d from the lens. The image of the object after reflection at the  mirror and a second refraction through the lens is at a distance v in front of the lens. Prove that  , u+v=2f

Asked by mridulabarua05 9th February 2019 1:21 PM

## What is the difference between convex lens and convex mirror?

Asked by gspublicschool 14th February 2019 1:51 PM

## Calculate the image distance formed from a convex lens having a focal length of 30cm and object distance being 20 cm . Comment about the nature of the image!??

Asked by gokulkrishnan186 18th February 2019 1:12 PM

## Lens combinations

Asked by alanpeter9611 24th February 2019 12:52 AM

## 'As an object is slowly brought from infinity to the focus of convex lens, the image travels from the focus to infinity.' Show this with the help of diagram with five different positions of the object.

Asked by gspublicschool 25th February 2019 7:18 PM

## For which position of the object magnification of convex lens is minus one

Asked by rakeshgowda51088 1st March 2019 8:53 PM

## Q. An object is placed at a distance of 24 cm in front of a convex lens of focal length 8 cm. (i) What is the nature of the image formed? (ii) Calculate the distance of the image from the lens. (iii) Calculate the magnification of the image.

Asked by akshushashu123 6th March 2019 10:00 AM

## The magnification of an image formed by a lens is – 1. If the distance of the image from the optical centre of the lens is 35 cm, where is the object placed ? What is the nature and focal length of the lens ? If the object is displaced 20 cm towards the optical centre of the lens, where would the image be formed and what will be its nature ? Draw a ray diagram to justify your answer.

Asked by biotechckt 10th March 2019 11:45 AM

## Why does the convex lens converge the rays of light?

Asked by rushabhjain.a 10th March 2019 9:21 PM

## beam of light converges at a point P. Now a lens is placed in the path of the convergent beam 12 cm from P. At what point does the beam converge if the lens is (a) a convex lens of focal length 20 cm, and (b) a concave lens of focal length 16 cm?

Asked by polyrelation 19th March 2019 8:29 PM

## 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?

Asked by rushabhjain.a 23rd March 2019 7:23 PM

## A sphere is placed in front of  a convex lens of focal length f. The radius of the sphere is much smaller compared to f. The image of the sphere would look spherical if the object distance is

Asked by bjayanta 24th March 2019 8:58 PM

## The length of an object kept at a distance of 25 cm from a convex lens is half of the object .Find the focal length of the mirror

Asked by anjly2723492 8th June 2019 9:55 AM

## An object placed in front of the convex lens at a distance of 25cm on the principal axis.  The focal length of lens is 15cm, at what distance the image is formed and writes the nature and size of the image.

Asked by craj.fru 2nd September 2019 9:45 AM

## A convex lens of focal length 24 cm produces a real image at 60 cm.find the distance of object from the lens

Asked by pranav1727chaudhari 2nd September 2019 11:35 AM

## an object is placed at a distance of 20cm from a convex lens on its principal axis its image is formed at other side of the lens at a distance of 18 cm form the lens . find the focal  length of the lens . is the image is magnified  ?

Asked by sandeepvishwakarma1116 12th October 2019 2:15 PM

## ⭕ Help me in this question....Thanks☺️

Asked by jhajuhi19 13th October 2019 5:45 PM

## How will the image of an object appear if half of the mirror/lens is covered completely? Please answer with diagram!

Asked by drhimasingh 30th November 2019 12:43 PM

## 17th sum

Asked by lovemaan5500 7th December 2019 8:52 PM

## Define main focus of convex lens

Asked by malkeetranu748 15th February 2020 8:05 PM

## Tell me in short(trick) to put place value of v, u, f in light lesson class 10

Asked by Jemiprici 19th February 2020 11:00 AM

## We wish to obtain an equal sized inverted image of a candle flame on a screen kept at a distance of 4m from the candle flame.  (a) What should be the focal length of the lens?

Asked by sm1980agrawal 23rd February 2020 7:31 AM

## An object is situated at adistance of f/2 from aconvex lens pf focal length f. Distance of image will be?

Asked by ansarimn999 6th March 2020 1:02 PM

## Which lens form virtual and erect image?

Asked by abhijeetkumar8513 10th April 2020 4:11 PM

## why focal length of convex lens is taken as positive

Asked by ammulusri97 29th April 2020 11:30 AM

## draw the ray diagram for getting a magnified inverted real image by using a convex lens

Asked by kushaltaak93 24th May 2020 7:55 PM

## do binocular lens use both concave and convex lenses? give reasons for using each lens?

Asked by saibaba1069 21st June 2020 7:52 PM

## How does the size of image change as the object is brought from closer to infinite towards the convex lens?

Asked by Mnjusoni720 9th July 2020 1:13 PM

## In physics,what kind of image will be form when concave and convex mirror and in lens are kept together

Asked by kmbhuvanakmbhuvana 19th July 2020 2:28 PM

## as object distance is decreased zero, that is the object is held very close to the lens ,the images in a diverging lens and converging lens become almost similar. can you find a simple qualitative explanation as to why? is there one different still?

Asked by kumargangwarn 19th July 2020 3:56 PM

## The image of an object formed by a lens is of magnification -1. If the distance between the object and it's image

Asked by durgeshsri8080 31st July 2020 10:45 PM

## f

Asked by durgeshsri8080 1st August 2020 6:43 AM

## Draw the ray diagram when the object is kept between F1 and 2F1 of the convex lens. with the help of the diagram mention the position and nature of the image formed.

Asked by ashokrathodrathod7 12th August 2020 12:15 PM

## Q - 10

Asked by majethiyarishat9566.12sdatl 18th September 2020 12:57 PM

## A convex lens has a focal length of 25 cm. Calculate the distance of the object from the lens if the image is to be formed on the opposite side of the lens at a distance of 75 cm from the lens. What will be the nature of the image

Asked by arajeevshashank 11th October 2020 12:33 PM

## 9.Find the position and the size of the virtual image formed when an object of 2cm tall is placed 20cm from : a)diverging lens of focal length 40cm b) converging lens of focal length 40cm .Draw labelled diagrams to show the formation of image

Asked by arajeevshashank 12th October 2020 5:49 PM

## 9.Find the position and the size of the virtual image formed when an object of 2cm tall is placed 20cm from : a)diverging lens of focal length 40cm b) converging lens of focal length 40cm .Draw labelled diagrams to show the formation of image

Asked by arajeevshashank 12th October 2020 5:55 PM

## A needle placed 50 cm from a lens forms an image on a screen placed 75cm on the other side of the lens. What is the type of the lens? Find it's focal length. If the length of the Needle is 5cm, what is the length of image?

Asked by ananyamohanty2005 28th December 2020 11:06 PM

## The image of an object formed by a lens is of magnification 2. If the distance between the object and its image is 60 cm, what is the focal length of the lens? If the object is moved 20 cm towards the lens, where would the image be formed? State reason and also draw a rayi diagramn support of your answer.

Asked by utpaltipu234 6th February 2021 9:06 PM

## Why convex lens can be used as a magnifying galss?

Asked by trisha.bansal1207 1st March 2021 1:42 PM

## 35. 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?

Asked by cskdhoni7ipl 21st March 2021 7:41 PM

## Why is object placed between 2f1 and f1 in a convex lens projector ?

Asked by pras.rangi 26th July 2021 9:06 AM

## State three characteristics of the image formed by a convex lens when the object is close to it.

Asked by asifmd2k9 6th February 2022 8:50 PM