Question

Large sized concave mirrors are used to focus sun rays in solar cookers and solar heaters. Make a solar cooker of your own by using this principle and exhibit in your school science fair.

Answer 1

Making of solar cooker :

1. A concave mirror focuses parallel sun rays at the focal point of the mirror. 

2. So with a small concave mirror .we can heat up and burn paper. 

3. In the same way make a big concave mirror to heat up a vessel. 

4. Make a wooden/ iron frame in the shape of TV dish. 

5. Cut acrylic mirror sheets into 8 or 12 pieces in the shape of isosceles triangles with a height equal to the radius of dish antenna. 

6. The bases of 8 or 12 triangles together make the circumference of the dish. 

7. Stick the triangle mirrors to the dish. 

8. Our solar heater/cooker is ready. 

9. Arrange it so that concave part faces sun. 

10. Find its focal point and place a vessel at that point. 

11. It will get heated. We can even cook rice in that vessel.