Final answer:
The relative humidity of the air inside the room when it is heated to 20°C is 25%.
Therefore, the correct answer is option (a) 25%.
Step-by-step explanation:
To find the relative humidity of the air inside the room, we need to consider the relationship between temperature and relative humidity. As air is heated, its ability to hold water vapor increases. This means that its saturation amount also increases.
Since the original air outside had a relative humidity of 50% at 0°C, when it is heated to 20°C, it can hold more water vapor, resulting in a relative humidity that is less than 50%. Therefore, the relative humidity of the air inside the room is less than 50%.
Therefore, the correct answer is option (a) 25%.
The question relates to the concept of relative humidity and how it changes with temperature. When outside air at 0°C with 50% relative humidity is brought inside and heated to 20°C, the relative humidity inside the room decreases. This is because the capacity of air to hold moisture increases with temperature.
Therefore, even though the amount of water vapor in the air remains constant, the air at 20°C can hold more moisture compared to when it was at 0°C, resulting in a lower relative humidity.
The correct answer is not directly provided in the excerpts but, through explanation and understanding of the concept, it can be reasoned that the relative humidity will be less than the initial 50% after the temperature increase.