Question

which of the following is an example of energy transfer by convection? a phone screen heats up when left in the sun. a cloud forms above a pool on a very hot day. an egg fries in a pan on a heated stove.

Explanation:

• For option A: A phone screen heating in the sun is radiation (heat from sun via electromagnetic waves), not convection.
• For option B: On a hot day, water from the pool evaporates (liquid to gas) and rises. As the warm, moist air rises, it cools (since air cools with increasing altitude), and the water vapor condenses into tiny water droplets to form a cloud. This involves the movement of fluid (air) carrying heat and moisture, which is convection.
• For option C: An egg frying in a pan is conduction (heat transfer through direct contact between the pan and the egg), not convection.

Answer:

B. A cloud forms above a pool on a very hot day.