Simple microscope : Number of convex lens one : : compound microscope : _______ - Science and Technology 1

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Simple microscope : Number of convex lens one : : compound microscope : _______



Simple microscope : Number of convex lens one : : compound microscope : Number of convex lenses two

Concept: Convex Lens
  Is there an error in this question or solution?
Chapter 7: Lenses - Find the correlation.


Complete the following table:

Instrument Number of Convex
Simple Microscope .............. ..............
Compound Microscope .............. ..............
Telescope .............. ..............

Where should an object be placed in front of a convex lens so as to obtain its real, inverted and magnified image?

If an object is at a considerable distance (or infinity) in front of a convex lens, where is the image formed?

 List some things that convex lens and concave mirror have in common.  

A convex lens has a focal length of 10 cm. At which of the following position should an object be placed so that this convex lens may act as a magnifying glass? 

(a) 15 cm
(b) 7 cm
(c) 20 cm
(d) 25 cm

A student did an experiment with a convex lens. He put an object at different distances 25 cm, 30 cm, 40 cm, 60 cm and 120 cm from the lens. In each case he measured the distance of the image from the lens. His results were 100 cm, 24 cm, 60 cm, 30 cm and 40 cm, respectively. Unfortunately his results are written in wrong order. 

 What is the focal length of this lens?


 What type of images can a convex lens make?

How would a pencil look like if you saw it through How would a pencil look like if you saw it through



In figure , name the ray which represents the correct path of light while emerging out through
a glass block. 


Name the different kinds of lenses. Draw diagrams to illustrate them.

A parallel oblique beam of light falls on a (i) convex lens, (ii) concave lens. Draw a diagram in each case to show the refraction of light through the lens.

Study the diagram below.

State three characteristics of the image

A convex lens forms an image of an object equal to the size of the object.draw a diagram to illustrate it.

For the object placed between optical centre and focus of a convex lens, the image is:

When you focus the image of a distant flag, whose shape is given below, on a screen using a convex lens, the shape of the image as it appears on the screen is





For which position of the object does a convex lens form a virtual and erect image? Explain with the help of a ray diagram.

Distinguish between:

Concave lens and Convex lens

i. Which type of microscope has the arrangement of lenses shown in the  adjoining figure?
ii. Label the figure correctly.
iii. Write the working of this microscope.
iv. Where does this microscope used?
v. Suggest a way to increase the efficiency of this microscope.

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

Yesh find out F1 and F2 of symmetric convex lens experimentally then which conclusion is true.

Observe the following figure and complete the table:

Points Answer
(i) Position of the object  
(ii) Position of the image  
(iii) Size of the image   
(iv) Nature of the image  

Draw neat diagram to show the
Convergent action of a convex lens,

If an object is placed in front of a convex lens beyond 2F1, then what will be the position, relative size, and nature of an image which is formed? Explain with a ray diagram.

Rewrite the following statement by selecting the correct option:
The power of a convex lens is 2.5 dioptres. Its focal length is ______________.

Point out the difference between a convex lens and a concave lens.

State the position of object, position of image, nature of image when: Convex lens is used as objective lens of photographic camera.

Draw a ray diagram to illustrate the determination of the focal length of a convex lens using an auxiliary plane mirror.

Diagram shows an object AB placed on the principal axis B of a convex lens placed in air. F1 and F2 are the two foci of the lens.

(i) Copy the diagram:
Draw a ray of light starting from B and passing through O. Show the same ray after refraction by the lens. Draw another ray from B which passes through F2 after refraction by the lens. Locate the final image
(ii) Is the image real or virtual?

For a specific glass lens f = 0.5 m. This is the only information given to the student. Which type of lens is given to him and what is its power?

_______ times larger images can be obtained by using a simple microscope.

_______ is a combination of two convex lenses with small focal length.

Object at 2F1 of a convex lens : Image at 2F2 : : Object at F1 : _______

: Object near the lens : : ______ :

Find the odd one out and give its explanation.

Find the odd one out and give its explanation.

Write the name.

The lens used in simple microscope.

Write scientific reason.

Adults need bifocal lens spectacle.

Observe the given figure and answer the following questions.

  1. Where is the above type of lens construction used?
  2. What type of image is formed by an objective lens?
  3. What happens instead of placing at Fo if the object is placed in between O and Fo?

Differentiate convex lens and concave lens.

  1. In which type of microscope do you find the lens arrangement as shown in the following diagram?
  2. Write about the working and the use of this microscope.

Distinguish between Concave lens and Convex lens.

Distinguish between:

Concave lens and Convex Lens

Distinguish between Concave lens and Convex Lens.

Distinguish between:

Concave lens and Convex Lens

Distinguish between:

Concave lens and Convex Lens


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