Correct Option
The correct option isA saucer of tea kept under a fan on a dry day.
Explanation
Evaporation is a surface phenomenon wherein a liquid transforms into vapor at any temperature below its boiling point. The rate at which evaporation occurs is governed by factors such as surface area, ambient temperature, humidity, and wind speed.
Scenario Analysis
- A cup of tea kept in a room with high humidity. A cup of tea kept in a room with high humidity: Incorrect. A cup offers a smaller surface area compared to a saucer. Additionally, high humidity means the atmosphere is already saturated with water vapor, which significantly decreases the rate of evaporation.
- A saucer of tea kept under a fan on a dry day. A saucer of tea kept under a fan on a dry day: Correct. This scenario combines three factors that maximize evaporation:
- Surface Area: The saucer provides a larger surface area than a cup, allowing more liquid particles to escape.
- Wind Speed: The fan ensures moving air, which carries away water vapor and maintains a concentration gradient favorable for evaporation.
- Humidity: A dry day implies low atmospheric humidity, allowing the air to absorb moisture more readily.
- A cup of tea kept inside a cupboard. A cup of tea kept inside a cupboard: Incorrect. This setup has a small surface area and lacks air circulation (wind speed), resulting in a minimal evaporation rate.
- A saucer of tea kept on a rainy day. A saucer of tea kept on a rainy day: Incorrect. Although the saucer provides a large surface area, a rainy day is characterized by high humidity. The high moisture content in the air inhibits the rate at which the liquid can evaporate.
Key Takeaway
The rate of evaporation is directly proportional to surface area, temperature, and wind speed, and inversely proportional to the humidity of the surrounding air.