An object is kept at a distance of 100cm from each of the above lenses. Calculate the (i) image distance and (ii) magnification in each of the two cases.
Download our app for free and get started
To find the image for convex lens,$\text{u}=-100\text{cm}$
$\text{f}=50\text{cm}$
$\text{v}=\frac{(\text{f }\times\text{ u})}{(\text{f}-\text{u})}=100\text{cm}$
magnification is 1 for concave lens,$\text{u}=-100\text{cm}$
$\text{f}=-25\text{cm}$
$\text{v}=\frac{-(\text{f }\times\text{ u})}{(\text{f}+\text{u})}=-20\text{cm}$
magnification is $\frac{\text{v}}{\text{u}}$ that's $\frac{20}{100}$ So, $\text{m}=0.2$
$\text{f}=50\text{cm}$
$\text{v}=\frac{(\text{f }\times\text{ u})}{(\text{f}-\text{u})}=100\text{cm}$
magnification is 1 for concave lens,$\text{u}=-100\text{cm}$
$\text{f}=-25\text{cm}$
$\text{v}=\frac{-(\text{f }\times\text{ u})}{(\text{f}+\text{u})}=-20\text{cm}$
magnification is $\frac{\text{v}}{\text{u}}$ that's $\frac{20}{100}$ So, $\text{m}=0.2$
Download our appand get started for free
Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
Similar Questions
- 1View SolutionWhich type of lens is:
- A converging lens, and which is.
- A diverging lens? Explain your answer with diagrams.
- 2View SolutionThe image of an object place at 60cm in front of a lens is obtained on a screen at a distance of 120cm from it. Find the focal length of the lens. What would be the lens? What would be the height of the image? If the object is 5cm high?
- 3View SolutionAn object 2cm tall is placed on the axis of a convex lens of focal length 5cm at a distance of 10m from the optical centre of the lens. Find the nature, position and size of the image formed. Which case of image formation by convex lenses is illustrated by this example?
- 4View SolutionAn object 4 cm in height, is placed at 15 cm in front of a concave mirror of focal length 10 cm. At what distance from the mirror should a screen be placed to obtain a sharp image of the object. Calculate the height of the image.
- 5View SolutionA lens of focal length 20cm is used to produce a ten times magnified image of a film slide on a screen. How far must the slide be placed from the lens ?
- 6View SolutionAn object is placed between infinity and the pole of a convex mirror. Draw a ray diagram and also state the position, the relative size and the nature of the image formed.
- 7View SolutionWhat is the effect on the size and position of the image of moving the object:
- Towards the lens, and
- Away from the lens?
- 8View SolutionA convex lens of focal length 25cm and a concave lens of focal length 10cm are placed in close contact with each other. Calculate the lens power of this combination.
- 9View SolutionIf the image formed by a mirror for all positions of the object placed in front of it is always erect and diminished, what type of mirror is it? Draw a ray diagram to justify your answer. Where and why do we generally use this type of mirror?
- 10View SolutionAt what distance should an object be placed from a convex lens of focal length 18 cm to obtain an image at 24 cm from it on the other side. What will be the magnification produced in this case?