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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
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
One-half of a convex lens is covered with a black paper. Will this lens produce a complete image of the object? Verify your answer experimentally. Explain your observations.
"A lens can form a magnified erect image as well as magnified inverted image of an object placed in front of it." State the nature of this lens and draw ray diagrams to justify the above statement. Mark the positions of O, F and 2F in the diagram.
Write one condition where it does not bend when entering a medium of different optical density.
State any two uses of convex lenses.
Name one simple optical instrument in which the above arrangement of convex lens is used.
A burning candle whose flame is 1.5 cm tall is placed at a certain distance in front of a convex lens. An image of candle flame is received on a white screen kept behind the lens. The image of flame also measures 1.5 cm. If f is the focal length of convex lens, the candle is placed:
(a) at f
(b) between f and 2f
(c) at 2f
(d) beyond 2f
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?
Calculate the focal length of a convex lens which produces a virtual image at a distance of 50 cm of an object placed 20 cm in front of it.
Which of the above two cases illustrates the working of a magnifying glass?
The focal lengths of four convex lenses P, Q, R and S are 20 cm, 15 cm, 5 cm and 10 cm, respectively. The lens having greatest power is :
(a) P
(b) Q
(c) R
(d) S
Draw a diagram to represent the second focus of a convex lens.
The focal length of a thin convex lens is ______ than that of a thick convex lens.
A lens forms an upright and magnified image of an object State whether the image is real or virtual
State two applications of a convex lens.
Yesh find out F1 and F2 of symmetric convex lens experimentally then which conclusion is true.
State the position of object, position of image, nature of image when: Convex lens is used as an erecting lens in terrestrial telescope.
Find the odd one out and give its explanation.
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
