Give a very short answer to the question given below.
The heat produced at a point due to concentration of sunlight by a convex lens burns a paper.
(a) Explain why it happens.
(b) Name the term (in the context of the lens used) given to the point at which the paper starts burning. what does the bright spot formed on the paper represent?
(a) Explain why it happens.
(b) Name the term (in the context of the lens used) given to the point at which the paper starts burning. what does the bright spot formed on the paper represent?
(a) A convex lens is a type of lens that the light rays that pass through it. When sunlight passes through a convex lens, it at a point called the . This of the convex lens is why the paper burns.
Sun has a huge amount of energy. When sunlight is focused on a small area of the paper, the energy of the light is concentrated in that area. This high concentration of energy causes the paper to heat up. If the concentration of energy is high enough, the paper may even catch fire.
(b) For burning of paper, the paper must be placed at of convex lens. The sun at a far distance from us. Therefore, the rays which are coming from the sun are parallel. When these parallel rays are falling on a convex lens, a of the sun is formed on the of the lens. Now if we place a white paper at the , we obtain a bright light spot which is the image of the sun.