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प्रश्न
Object at 2F1 of a convex lens : Image at 2F2 : : Object at F1 : _______
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उत्तर
Object at 2F1 of a convex lens : Image at 2F2 : : Object at F1 : Image at infinity
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संबंधित प्रश्न
A 1 cm high object is placed at a distance of 2f from a convex lens. What is the height of the image formed?
f the image formed by a convex lens is of the same size as that of the object, what is the position of the image with respect to the lens?
Where should an object be placed in front of a convex lens so as to obtain its virtual, erect and magnified image?
Define principal axis, principal focus and focal length of a convex lens.
Describe with the help of a ray-diagram, the formation of image of a finite object placed in front of convex lens between f and 2f. Give two characteristics of the image so formed.
Describe with the help of a ray diagram the nature, size and position of the image formed when an object is placed in front of a convex lens between focus and optical centre. State three characteristics of the image formed.
With the help of a labelled diagram explain how a convex lens converges a beam of parallel light rays. Mark the principal axis, optical centre, principal focus and focal length of the convex lens on the diagram.
Find the position and nature of the image of an object 5 cm high and 10 cm in front of a convex lens of focal length 6 cm.
In figure , name the ray which represents the correct path of light while emerging out through
a glass block.
Draw a diagram to represent the second focus of a convex lens.
A parallel oblique beam of light falls on a convex lens. Draw a diagram to show the refraction of light through the lens.
The given below figure shows an object OA and its image IB formed by a lens
. 
draw suitable rays to locate the lens and its focus.
Observe the following figure and answer the questions.
a) Which optical instrument shows arrangement of lenses as shown in the figure?
b) Write in brief the working of this optical instrument.
c) How can we get different magnifications in this optical instrument?
d) Draw the figure again and labelled it properly
Answer the following question.
List four precautions which a student should observe while determining the focal length of a given convex lens by obtaining an image of a distant object on a screen.
A candle is placed between f and 2f a convex lens. Draw a ray diagram showing the position of the image.
We can burn a piece of paper by focussing the sun rays by using a particular type of lens. Name the type of lens used for the above purpose. Draw a ray diagram to support your answer.
Can one bum a piece of paper in daylight by just using a convex lens instead of a match or any direct flame? Support your answer with the help of an appropriate ray diagram.
Write the name.
The lens used in simple microscope.
Write scientific reason.
Adults need bifocal lens spectacle.
