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प्रश्न
Describe with a suitable diagram, how a convex mirror diverges a parallel beam of light rays. Mark clearly the pole, focus and centre of curvature of concave mirror in this diagram.
उत्तर
When a parallel beam of light, also parallel to the principle axis, is incident on a convex mirror, it will reflect from the mirror, and the reflected rays will appear to come from a point which is called the focus (F) of the convex mirror. So, a convex mirror has a virtual focus.
Ray diagram- A convex mirror diverges a parallel beam of light rays.
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संबंधित प्रश्न
Analyse the following observation table showing variation of image distance (v) with object distance (u) in case of a convex lens and answer the questions that follow, without doing any calculations:
| S. No. | Object distance u(cm) | Image distance v(cm) |
| 1 | −90 | +18 |
| 2 | −60 | +20 |
| 3 | −30 | +30 |
| 4 | −20 | +60 |
| 5 | −18 | +90 |
| 6 | −10 | +100 |
(a) What is the focal length of the convex lens? Give reason in support of your answer.
(b) Write the serial number of that observation which is not correct. How did you arrive at this conclusion?
(c) Take an appropriate scale to draw ray diagram for the observation at S. No. 4 and find the approximate value of magnification.
Which type of mirror has:
positive focal length?
Why can you not use a concave mirror as a rear-view mirror in vehicles?
How will you distinguish between a plane mirror, a concave mirror and a convex mirror without touching them?
If a driver has one convex and one plane rear-view mirror, how would the images in each mirror appear different?
Two big mirrors A and B are fitted side by side on a wall. A man is standing at such a distance from the wall that he can see the erect image of his face in both the mirrors. When the man starts walking towards the mirrors, he find that the size of his face in mirror A goes on increasing but that in mirror B remains the same.
(a) mirror A is concave and mirror B is convex
(b) mirror A is plane and mirror B is concave
(c) mirror A is concave and mirror B is plane
(d) mirror A is convex and mirror B is concave
The nature of image formed by a convex mirror when the object distance from the mirror is less than the distance between pole and focal point (F) of the mirror would be ______.
The image formed by a convex mirror is always ______.
If the object is at infinity in front of a convex mirror the image is formed at infinity.
Higher-Order Thinking Skills:
A convex mirror is in water. What should be the change in its focal length?
