_______ is a combination of two convex lenses with small focal length. - Science and Technology 1

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

Options

  • simple microscope

  • compound microscope

  • telescope

  • none of these

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Solution

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

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

RELATED QUESTIONS

To determine the approximate focal length of the given convex lens by focussing a distant object (say, a sign board), you try to focus the image of the object on a screen. The image you obtain on the screen is always

(a) erect and laterally inverted

(b) erect and diminished

(c) inverted and diminished

(d) virtual, inverted and diminished


When a ray of light enters from one medium to another having different optical densities it bends. Why does this phenomenon occur?


Complete the following table:

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

A beam of light travelling in a rectangular glass slab emerges into air. Draw a ray-diagram indicating the change in its path.


What type of lens would you use as a magnifying glass? How close  must the object be to the lens?


Fill in the following blank with suitable word: 

The image in a convex lens depends upon the distance of the ........... from the lens.


Define principal axis, principal focus and focal length of a convex lens.


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


What is the position of image when an object is placed at a distance of 10 cm from a convex lens of focal length 10 cm?


A convex lens of focal length 0.10 m is used to form a magnified image of an object of height 5 mm placed at a distance of 0.08 m from the lens. Calculate the position, nature and size of the image. 


What kind of lens can form: 

an inverted diminished image? 


A light ray does not bend at the boundary in passing from one medium to the other medium if the angle of incident is:


Show by a diagram the refraction of two light rays incident parallel to the principal axis on a convex lens by treating it as a combination of a glass block and two triangular glass prisms.


The diagram alongside shows a lens as a combination of a glass block and two prisms.  Name the lens formed by the combination. 


A lens forms an inverted image of an object.  what kind of lens is this?


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.


The image obtained while finding the focal length of convex lens is ....................


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  

An object of height 4.0 cm is placed at a distance 24 cm in front of a convex lens of focal length 8 cm. Draw a ray diagram to find the position of image. State the characteristics of the image.

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 object, on the screen?


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 : The focal length of the 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.


Write the three characteristics of the image formed by a convex lens of focal length 20 cm for the object at distance (i) 10 cm, (ii) 30 cm, (iii) 40 cm, (iv) 60 cm from the lens.


How will you determine the focal length of a convex lens by the plane mirror method?


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.


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


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


: 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


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