This set of Solar Energy Multiple Choice Questions & Answers (MCQs) focuses on “Solar Cookers – 1”.
1. What is solar cooker?
a) Uses direct sunlight to produce heat and cook food
b) Uses solar energy to evaporate water and collect it within the same closed system
c) Uses solar energy to dry substances
d) Uses concentrated solar power to for industry
Explanation: Solar cookers are devices that use direct sunlight to produce heat and cook food. Solar dryers are devices that use solar energy to dry substances. Devices that use solar energy to evaporate water and collect its condensate within the same closed system are called solar stills.
2. What is pasteurization?
a) Process of treating water by biological techniques
b) Process of treating water by heating it mildly
c) Process of producing water
d) Process of capturing sun’s heat
Explanation: Pasteurization is the process of treating water, packaged and non-packaged food by heating it mildly. This is done to eliminated pathogens and extend shelf life.
3. Which of the following principles is used to concentrate sunlight in solar cookers?
c) Specular reflection
Explanation: Specular reflection is used to concentrate sunlight in solar cookers. Evaporation is the process of liquid, particularly water turning into gas. Rarefaction is the reduction in density of air or gas.
4. Which of the following majorly affects the phenomenon of concentrating sunlight?
a) Non-reflecting surface
b) Black surface
c) Type of food
d) Geometry of the reflecting structure
Explanation: Geometry of the reflecting structure majorly affects the phenomenon of concentrating sunlight. The amount of sunlight being concentrated can be controlled by the geometry of the reflecting structure.
5. What is the typical temperature (range) used in domestic cooking? Note that C indicates Celsius.
a) 50 – 70 degree C
b) 1000 degree C
c) 3500 degree C
d) 300 – 500 degree C
Explanation: The typical temperature used in domestic cooking is around 65 degree C. It falls in the range of 50 – 70 degree C. Temperatures beyond 1000 degree C are used for industrial purposes.
6. What is the maximum temperature used in cooking? Note that C indicates Celsius
a) 100 degree C for boiling water and related dishes
b) 400 degree C for grilling and searing
c) 800 degree C for melting metals
d) 30 degree C for melting food items like butter
Explanation: The maximum temperature used in cooking is 400 degree C for grilling and searing purposes. Boiling water and melting food items like butter do not require temperatures beyond 100 degree C. Temperatures beyond 500 degree C are used in industries.
7. The cooking pan used in solar cookers convert ______ energy to ______ energy.
a) electrical, heat
b) heat, light
c) light, heat
d) electrical, light
Explanation: The cooking pan used in solar cookers convert light energy to heat energy. After reflecting and concentrating the light onto the cooking pan, the pan conducts heat to cook the required food/substance.
8. Which of the following materials are used to make the cooking pan in a solar cooker?
Explanation: Iron is a good conductor of heat. It is used to make the cooking pan to heat food in a solar cooker. Wood, plastic and rubber are thermal insulators.
9. Which of the following are used to manufacture parabolic dish concentrator?
a) Anodized aluminum
Explanation: Parabolic dish (and trough) are made of anodized aluminum (or coated with aluminum) to reflect sunlight and concentrate it onto a receiver. Wood, iron and bakelite are not used as they do not have reflective properties. Moreover, wood and bakelite are thermal insulators.
10. Which of the following pot surfaces are preferred for solar cookers?
a) White coloured
b) Black coloured
c) Red coloured
d) Silver coloured
Explanation: Black coloured pot surfaces are best suited to be used on cooking pans of solar cookers. This is because black absorbs most amount of heat as compared to any other colour. White, aluminum and silver coated surfaces are good reflectors of light and heat.
11. Convection should be reduced by isolating air inside the cooker from air outside the cooker.
Explanation: Convection should be reduced by isolating air inside the cooker from air outside the cooker. This is to prevent escape of heat via convection.
12. Covering the pot with a glass lid ________ convection.
b) does not affect
c) changes the direction of
Explanation: Covering the pot with a glass lid reduces convection. This results in a greenhouse effect thereby trapping heat to cook the food inside the pot.
13. Evacuated tube solar cookers use ________ glass tube for the cooking chamber.
a) highly insulated
b) thermal conducting
d) cone shaped
Explanation: Evacuated tube solar cookers use highly insulated double-wall glass tube for the cooking chamber. They do not require large reflectors to concentrate sunlight.
14. Which of the following best describes the working of a solar cooker?
a) Concentrating sunlight → trapping heat → cooking
b) Concentrating sunlight → converting light to heat energy → trapping heat →cooking
c) Concentrating sunlight → cooking → trapping heat
d) Trapping heat → converting heat to light energy → radiating light → cooking
Explanation: Sunlight is concentrated onto a receiver by reflective surfaces of the structure. This light is converted to heat by the receiver. The heat is then trapped by the pots used for cooking.
15. Solar cookers do have operating costs.
Explanation: Solar cookers have negligible or no operating costs. Since the entire system is built to be self-operating, it does not require any external fuel for initiation and operation.
Sanfoundry Global Education & Learning Series – Solar Energy.
To practice all areas of Solar Energy, here is complete set of 1000+ Multiple Choice Questions and Answers.