2022 · Q20
Which one of the following statements is true with regard to a greenhouse
General KnowledgePhysics
- AThe shorter wavelength infrared radiations from the Sun can enter into the greenhouse while longer wavelength infrared radiations from the ground and the plants inside the greenhouse cannot pass back out through the glass
- BThe shorter wavelength infrared radiations from the Sun can enter into the greenhouse and the longer wavelength infrared radiations from the ground and the plants inside the greenhouse can also pass back out through the glass.
- CThe shorter wavelength infrared radiations from the Sun cannot enter into the greenhouse while longer wavelength infrared radiations from the ground and the plants inside the greenhouse can pass back out through the glass
- DNo infrared radiation can pass through the glass of the greenhouse.
Explanation
Glass is transparent to the short-wavelength (visible/near-infrared) radiation arriving from the Sun, but it absorbs the longer-wavelength infrared re-radiated by the warm ground and plants inside. The trapped long-wave radiation heats the greenhouse — the greenhouse effect. Options B, C and D contradict this selective transmission.