Question

Nishigandha kept a vessel containing all the ingredients for making tea in a solar cooker. Shivani kept a similar vessel on a stove. Whose tea will be ready first and why?

Answer 1

Shivani's tea will be prepared first.
In Shivani's case, the intensity of the flame in contact with the vessel is very high due to which the flow of heat will be faster. Thus, the time taken by the tea to reach its boiling point will be less. Hence, tea will be prepared fast.
In the case of Nishigandha, the intensity of radiation reaching the vessel is not as high as compared to the stove's flame. Thus, the flow of heat will be slower in this case due to which more time will be taken to reach the boiling temperature of the tea. Hence, tea will be prepared at a slower rate.