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प्रश्न
Distinguish between:
Concave lens and Convex lens
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उत्तर
| Concave lens | Convex lens | |
| 1. | It is a diverging lens because it diverges the rays falling on it. | It is a converging lens because it converges the rays falling on it. |
| 2. | It is thin at the center and bulged at the edge. | It is thin at the edge and bulged at the centre. |
| 3. | The image formed by concave lens is always diminished and virtual. | The image formed by convex lens can be real as well as virtual. Also, the image formed can be diminished as well as magnified. |
| 4. | It has a virtual focus. | It has a real focus. |
संबंधित प्रश्न
A student wants to project the image of a candle flame on the walls of school laboratory by using a lens:-
(a) Which type of lens should be use and why?
(b) At what distance in terms of focal length 'F' of the lens should be place the candle flame so as to get (i) a magnified, and (ii) a diminished image respectively on the wall?
(c) Draw ray diagram to show the formation of the image in each case?
Which of the following lenses would you prefer to use while reading small letters found in a dictionary?
An object is placed at a distance of 15 cm from a convex lens of focal length 20 cm. List four characteristics (nature, position, etc.) of the image formed by the lens.
State whether convex lens has a real focus or a virtual focus.
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
If the object is moved to a point only 3 cm away from the lens, what is the new position, height and nature of the image?
A convex lens of focal length 15 cm produces a magnification of +4. The object is placed:
(a) at a distance of 15 cm
(b) between 15 cm and 30 cm
(c) at less than 15 cm
(d) beyond 30 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.
Which of the object distances gives the biggest image?
A camera fitted with a lens of focal length 50 mm is being used to photograph a flower that is 5 cm in diameter. The flower is placed 20 cm in front of the camera lens.
At what distance from the film should the lens be adjusted to obtain a sharp image of the flower?
The diagrams (a) and (b) in Figure below show the refraction of a monochromatic ray of light through a parallel sided glass block and a prism respectively. In each diagram, label the incident, refracted emergent rays and the angle of deviation.
Study the diagram below.
what are the points O, O’ called?
A converging lens forms the image of an object placed in front of it, beyond 2F2 of the lens. Draw a ray diagram to show the formation of the image.
In the following cases, where must an object be placed in front of a convex lens so that the image formed is inverted and enlarged?
In the following cases, where must an object be placed in front of a convex lens so that the image formed is upright and enlarged?
The image obtained while finding the focal length of convex lens is ....................
Define the terms principal foci and focal lengths as applied to a convex lens, and show them with the help of proper diagrams.
A beam of light is incident through the holes on side A and emerges out of the holes on the other face of the box as show in the figure. Which of the following could be inside the box?
Distinguish between:
Concave lens and Convex Lens
