Answer. we should not use plastic sheet becz it is not a good absorber of heat and like glass sheet it can’t create the greenhouse effect by trapping sun rays ..

Convex Security Mirrors The reflective surface bulges outwards toward the light source which results in a distorted image but an expanded field of view. It is this wide-angle field of view which makes convex mirrors highly suitable for security applications in shops and retail premises.

Answer: no cellophane paper can’t be replaced in place glass sheet as it is plastic.

Hint: The sun rays pass through the glass sheet which is used as a cover in the solar cooker and these sun rays are absorbed inside the cooker. It traps more rays of the sun, thus it is helpful in heating the food item.

Although there is a lot of variation between designs of solar cookers, in general they all fall under three categories: box, parabolic, and panel.

The sun is Earth’s major external source of heat energy. The sun’s energy travels to Earth as electromagnetic radiation.

Solar cooker works on the principle that sunlight warms the pot, which is used for cooking the food. Now, this warming of the pot occurs by converting light energy to heat energy. A solar cooker lets the UV light rays in and then transforms them into longer infrared light rays that cannot escape.

The solar cooker cannot be used at night and during cloudy weather. It takes more time to cook food. The direction of the solar cooker is to be changed continuously towards the direction of the Sun. Solar energy is not available uniformly all the time and at all places.

Solar cookers benefit the environment by:

• Using clean, renewable, and readily available solar energy as fuel.
• Preserving natural resources by not requiring the use of wood or other biomass fuels to cook.
• Not producing dangerous emissions which pollute local environments and contribute to climate change.

A solar cooker is a device which uses the energy of direct sunlight to heat, cook or pasteurize drink and other food materials.