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Question
When a spherical mirror is held towards the sun and its sharp image is formed on a piece of carbon paper for some time, a hole is burnt in the carbon paper.
- What is the nature of spherical mirror?
- Why is a hole burnt in the carbon paper?
- At which point of the spherical mirror the carbon paper is placed?
- What name is given to the distance between spherical mirror and carbon paper?
- What is the advantage of using a carbon paper rather than a white paper?
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Solution
- The spherical mirror is concave.
- A lot of the sun’s heat rays are concentrated at the point of the sun’s image, which burns a hole in carbon paper.
- The carbon is placed at the focus.
- The distance between the spherical mirror and the carbon paper is named the focal length.
- A black carbon paper absorbs more heat rays and hence burns a hole more easily (than a white paper).
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