Question

Which of the following will improve the efficiency of a solar cooker?
A) Regularly orienting the solar cooker according to the sun
B) Increasing the span of the glass sheet on the top
C) Using black coated utensils
D) All of the above

Answer 1

Hint: To improve the efficiency of a solar cooker, we must make sure that it receives maximum sunlight. Different methods are used so that the solar cooker receives the maximum energy to cook food. We have to take into consideration each option given and find out if it will help to accumulate maximum energy in the device.

Complete answer:
The solar cooker, as the name suggests, uses solar energy radiated by the sun to cook food. It works on the principle of transfer of energy through different forms. Here, light energy is being converted into heat energy.
Now, as the earth rotates around its axis, the position of the sun seems to change due to it. So, to receive maximum energy, the cooker has to be oriented in the direction of the sunlight.
The solar cooker is made up of an insulating metal box that is covered by a transparent glass sheet.
We can see a solar cooker in the below picture:

The infrared rays coming from the sun are allowed to enter the box through a glass sheet. So, if the span of the sheet is increased, more rays will be directed towards the box and hence increasing its energy.
A blackbody is a perfect emitter and absorber. This means that it absorbs all the radiations of different wavelengths and gets heated up much quicker than other colors. Also, it doesn’t allow the heat energy to escape in the environment and thus increases the efficiency of the cooker.
Therefore all the statements given in the options are correct and they can increase the efficiency of the solar cooker. So, option (D) is correct.

Note:
Although solar cooker is a good substitution of natural gas as it uses a renewable source of energy i.e. Solar Energy. But, the disadvantages are major in this case. Firstly, solar energy is not available during rainy days & nights. So the cooker can’t be used on such days. Moreover, we can cook only those things which are boiled and not anything fried as the heat required for frying cannot be obtained in a solar cooker. Also, a lot of time is required to cook food in the solar cooker.